Perusals & Progressions: Detect Magic

Continuing through through the 1st-level cleric spells, we come to detect magic.  I don't expect that this spell will present too many problems or revelations as I go through its history, but you never know.

ORIGINAL D&D (1974)

Detect Magic: A spell to determine if there has been some enchantment laid on a person, place or thing. It has a limited range and short duration. It is useful, for example, to discover if some item is magical, a door has been "held" or "wizard locked", etc.

This is about as basic and uncomplicated as this spell can get.  It's the first spell described in OD&D, and note that the range and duration aren't defined with specific numbers.  It seems odd, given the game's origins in wargaming, that these categories wouldn't be numerically defined, but perhaps Dave and Gary didn't think that this spell required it.  They must have changed their minds pretty quickly, because a year later in Supplement I: Greyhawk it's given a range of 6" and a duration of 2 turns.

The cleric and magic-user versions of the spell are identical.

HOLMES D&D (1977)

Detect Magic — Level: 1; Range: 60 feet; Duration: 2 turns
A spell to determine if there has been some enchantment laid on a person, place or thing. It has a limited range and short duration. It is useful, for example, to discover if some item is magical, a door has been "held" or "wizard locked," etc.

This is the exact same wording as in OD&D, and the range and duration from Supplement I have been incorporated.

B/X (1981)

Detect Magic
Range: 60'
Duration: 2 turns
This spell determines if there has been an enchantment laid upon a person, place, or thing, causing any magic item within 60' to glow. Several items may be tested until the spell's duration has ended. It is useful, for example, to discover if some item is magical, if a door has been magically "held" or "wizard locked" (see Magic-user and Elf Spells), and so forth.

There are two minor changes here: the magic that is detected now glows, and there are very rough guidelines as to how many items can be "tested" during the spell's duration.  What this means is unclear; if everything magical within the range glows, why would items need to be tested at all?  There shouldn't be a limit on the number of items detected, as long as they're all within 60 feet.

BECMI (1983)

Detect Magic
Range: 0
Duration: 2 turns
Effect: Everything within 60'
When this spell is cast, the cleric will see magical objects, creatures, and places within range glow. It will not last very long, and should be saved until the cleric wants to see if something found during an adventure is, in fact, magical. For example, a door may be held shut magically, or a treasure found might be enchanted; in either case, the magic item, creature, or effect will glow when it is within the effect.

The glow caused by this spell is clarified to be something that only the caster can see. To reflect that, the range of the spell has been changed to 0, to indicate that it affects the caster rather than the magic being detected.

The magic-user version of the spell ends with a different example: "Shortly after casting this spell, a magic-user walks into a room containing a door locked by magic, a magical potion laying nearby, and a treasure chest containing a magic wand. All the magic will glow, but only the door and potion will be seen: the light of the glowing wand is hidden by the treasure chest."  This clarification that the spell is a line-of-sight effect, and doesn't work through solid objects, is a direct contradiction of AD&D.

RULES CYCLOPEDIA (1991)

Detect Magic
Range: 0
Duration: 2 turns
Effect: Everything within 60'
When this spell is cast, the cleric will see a glow surround magical objects, creatures, and places within the spell's effect. The glow will not last very long; clerics should normally use the spell only when they want to know if particular objects already within sight are, in fact, magical. For example, a door may be held shut magically, a stranger might actually be an enchanted monster, or a treasure might be enchanted.

This spell is pretty much exactly from BECMI, and just as in BECMI the magic-user version of the spell clarifies that the caster can only detect magic on things that are in plain sight.  It seems like a bit of an editorial oversight not to include that in both versions.

That's the Basic line done, and as usual it's all very consistent.  Now let's move to AD&D.

AD&D 1st EDITION (1978)

Detect Magic (Divination)
Level: 1
Range: 3"
Duration: 1 turn
Area of Effect: 1" path, 3" long
Components: V, S, M
Casting Time: 1 round
Saving Throw: None
Explanation/Description: When the detect magic spell is cast, the cleric detects magical radiations in a path 1" wide, and up to 3" long, in the direction he or she is facing. The caster can turn 60 degrees per round. Note that stone walls of 1' or more thickness, solid metal of but 1/12' thickness, or 3' or more of solid wood will block the spell. The spell requires the use of the cleric’s holy (or unholy) symbol.

The range, duration, and area of effect are all changed, and the spell can detect things through solid objects (to a point).  I always find it odd how different Gary went with some things in AD&D, and that Moldvay and Mentzer didn't follow his lead on the Basic line for consistency.  There's also some trademark Gygaxian overcomplication here, with the spell being blocked by 1/12' of metal; just call it an inch, Gary!

The magic-user version of the spell has a duration of 2 rounds/level, an area of effect that stretches to 6", and a casting time of 1 segment.  It also doesn't require a holy symbol, obviously.

Druids can cast this spell, and their version has a duration of 4 rounds/level, an area of effect 4" long, and a casting time of 3 segments.  Illusionists cast it as a 2nd level spell, but their version is otherwise the same as that for magic-users.

AD&D 2nd EDITION (1989)

Detect Magic (Divination)
Sphere: Divination
Range: 30 yards
Components: V, S, M
Duration: 1 turn
Casting Time: 1 round
Area of Effect: 10-foot path
Saving Throw: None
When the detect magic spell is cast, the priest detects magical radiations in a path 10 feet wide and up to 30 yards long, in the direction he is facing.  The intensity of the magic can be detected (dim, faint, moderate, strong, overwhelming). The caster has a 10% chance per level to determine the sphere of the magic, but unlike the wizard version of the spell, the type of magic (alteration, conjuration, etc.) cannot be divined. The caster can turn, scanning a 60-degree arc per round. A stone wall of 1 foot or more thickness, solid metal of one-inch thickness, or a yard or more of solid wood blocks the spell.
The spell requires the use of the priest's holy symbol.

The magic-user version of the spell has different range and duration as in 1e, and as noted above can detect the type/school of magic.  It also ends with the following paragraph that's not in the cleric version.

Magical areas, multiple types of magic, or strong local magical emanations may confuse or conceal weaker radiations. Note that this spell does not reveal the presence of good or evil, or reveal alignment. Other-planar creatures are not necessarily magical.

It's interesting that the cleric version of the spell has had its range converted to yards, whereas the magic-user version is still using feet.  In previous editions the magic-user spell had more range, but now they've been swapped.  Just as it did with detect evil, 2e introduces the idea of different aura intensities, but doesn't show how they are actually determined.

AD&D 2nd EDITION REVISED (1995)

No need to reproduce these versions of the spell, because they're identical to those in 2e except for some minor formatting changes.

D&D 3rd EDITION (2000)

Detect Magic
Universal
Level: Brd 0, Clr 0, Drd 0, Sor/Wiz 0
Components: V, S
Casting Time: 1 action
Range: 60 ft.
Area: Quarter circle emanating from you to the extreme of the range
Duration: Concentration, up to 1 minute/level (D)
Saving Throw: None
Spell Resistance: No 

You detect magical auras. The amount of information revealed depends on how long you study a particular area or subject: 

1st Round: Presence or absence of magical auras. 

2nd Round: Number of different magical auras and the strength of the strongest aura. 

3rd Round: The strength and location of each aura. If the items or creatures bearing the auras are in line of sight, you can make Spellcraft skill checks to determine the school of magic involved in each. (Make one check per aura; DC 15 + spell level, or 15 + half caster level for a non-spell effect.) 

Magical areas, multiple types of magic, or strong local magical emanations may confuse or conceal weaker auras. 

Aura Strength: An aura’s magical power and strength depend on a spell’s functioning spell level or an item’s caster level. 

Strength	Functioning Spell Level	Item Caster Level
Dim	0-level or lingering aura	Lingering aura
Faint	1st-3rd	1st-5th
Moderate	4th-6th	6th-11th
Strong	7th-9th	12th-20th
Overwhelming	Artifact or deity-level magic	Beyond mortal caster

If an aura falls into more than one category, detect magic indicates the stronger of the two. 

Length Aura Lingers: How long the aura lingers depends on its original strength: 

Original Strength	Duration
Faint	1d6 minutes
Moderate	1d6 x 10 minutes
Strong	1d6 hours
Overwhelming	1d6 days

Note: Each round, you can turn to detect things in a new area. The spell can penetrate barriers, but 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt blocks it.  Outsiders and elementals are not magical in themselves, but if they are conjured, the conjuration spell registers.

Just as detect evil did, 3rd edition adds a lot in terms of determining the strength of an aura.  The area of effect, which started as a sphere in OD&D and became a narrow line in AD&D, is now a quarter circle.  The only simplification that's been done is that the cleric and magic-user versions of the spell are the same, rather than having their own arbitrarily different ranges and durations.  I should also mention that it's become a 0-level spell, effectively a cantrip, which means that it's much more likely to see use during a game.  The school has also changed from divination to universal, probably so that there won't be any specialist wizards who don't have access to it.

D&D 3.5th EDITION (2003)

Detect Magic
Divination
Level: Brd 0, Clr 0, Drd 0, Sor/Wiz 0
Components: V, S
Casting Time: 1 standard action
Range: 60 ft.
Area: Cone-shaped emanation
Duration: Concentration, up to 1 minute/level (D)
Saving Throw: None
Spell Resistance: No 

You detect magical auras. The amount of information revealed depends on how long you study a particular area or subject: 

1st Round: Presence or absence of magical auras. 

2nd Round: Number of different magical auras and the power of the most potent aura. 

3rd Round: The strength and location of each aura. If the items or creatures bearing the auras are in line of sight, you can make Spellcraft skill checks to determine the school of magic involved in each. (Make one check per aura; DC 15 + spell level, or 15 + half caster level for a nonspell effect.) 

Magical areas, multiple types of magic, or strong local magical emanations may distort or conceal weaker auras. 

Aura Strength: An aura’s power depends on a spell’s functioning spell level or an item’s caster level. If an aura falls into more than one category, detect magic indicates the stronger of the two.

Spell or Object	Faint	Moderate	Strong	Overwhelming
Functioning spell (spell level)	3rd or lower	4th-6th	7th-9th	10th+ (deity-level)
Magic item (caster level)	5th or lower	6th-11th	12th-20th	21st+ (artifact)

Lingering Aura: A magical aura lingers after its original source dissipates (in the case of a spell) or is destroyed (in the case of a magic item). If detect magic is cast and directed at such a location, the spell indicates an aura strength of dim (even weaker than a faint aura). How long the aura lingers at this dim level depends on its original power. 

Original Strength	Duration of Lingering Aura
Faint	1d6 rounds
Moderate	1d6 minutes
Strong	1d6x10 minutes
Overwhelming	1d6 days

Outsiders and elementals are not magical in themselves, but if they are summoned, the conjuration spell registers. 

Each round, you can turn to detect magic in a new area. The spell can penetrate barriers, but 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt blocks it. 

Detect magic can be made permanent with a permanency spell.

There have been some formatting changes, and a switch back to the divination school, but the 3.5e spell is much the same as that from 3e.  The major difference is that the durations for lingering auras have been greatly reduced, except for those of overwhelming power.

D&D 4th EDITION

Detect Magic (Trained Only)
Your knowledge of magic allows you to identify magical effects and sense the presence of magic. 

Identify Conjuration or Zone: Minor action.
✦ DC: DC 15 + one-half the power’s level. You must be able to see the effect of the conjuration or zone.
✦ Success: You identify the power used to create the effect and its power source and keywords.
✦ Failure: You can’t try to identify the effect again during this encounter. 

Identify Ritual: Standard action.
✦ DC: DC 20 + one-half the ritual’s level. You must be able to see or otherwise detect the ritual’s effects.
✦ Success: You identify the ritual and its category.
✦ Failure: You can’t try to identify the ritual again until after an extended rest. 

Identify Magical Effect: Standard action.
✦ DC: DC 20 + one-half the effect’s level, if any. You must be able to see or otherwise detect the effect.
✦ Not a Power or a Ritual: The magical effect must be neither from a magic item nor the product of a power or a ritual.
✦ Success: You learn the effect’s name, power source, and keywords, if any of those apply.
✦ Failure: You can’t try to identify the effect again until after an extended rest. 

Sense the Presence of Magic: 1 minute.
✦ DC: DC 20 + one-half the level of a magic item, power (conjuration or zone), ritual, or magical phenomenon within range.
✦ Area of Detection: You can detect magic within a number of squares equal to 5 + your level in every direction, and you can ignore any sources of magical energy you’re already aware of. Ignore all barriers; you can detect magic through walls, doors, and such.
✦ Success: You detect each source of magical energy whose DC you meet. You learn the magic’s power source, if any. If the source of magical energy is within line of sight, you pinpoint its location. If it’s not within line of sight, you know the direction from which the magical energy emanates, but you don’t know the distance to it.
✦ Failure: Either you detected nothing or there was nothing in range to detect. You can’t try again in this area until after an extended rest.

In 4th edition, detect magic is no longer a spell, and has become an application of the Arcana skill.  "Sense the Presence of Magic" is the use that's closest to the old spell, but its implementation is so different that there's not much point in comparing it to other editions.

D&D 5th EDITION (2014)

Detect Magic
1st-level divination (ritual)
Casting Time: 1 action
Range: Self
Components: V, S
Duration: Concentration, up to 10 minutes
For the duration, you sense the presence of magic within 30 feet of you. If you sense magic in this way, you can use your action to see a faint aura around any visible creature or object in the area that bears magic, and you learn its school of magic. if any.
The spell can penetrate most barriers, but it is blocked by 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt.

5th edition pares things back, getting rid of the differing power levels and lingering auras.  The area of effect has returned to being a radius.

D&D Nth EDITION

This spell is fairly consistent in its basics across editions, with only two major contradiction.  The first of these is whether it can detect magic through barriers.  As I'll do in most instances, I'm going with the majority here, and ruling that it can.  The second is the spell's area of effect; is it a radius, a line, or a cone?  I prefer detect magic to be a fairly wide-ranging spell, so I'm going to go with a radius effect.

I've kept the detection of lingering auras, but have gone my own way with the durations, having them progress as rounds/turns/hours/days.  It's an easier progression to remember than either of the two used for 3e and 3.5e.

For aura strength, I considered consolidating the ranges used for spells and magic items, but I'm not yet sure how I'm dealing with things like caster level for magic items.  For now I'll stick with the 3e method until I've looked into things more closely.

Detect Magic
Divination
Level: Cleric 1, Magic-User 1
Components: V,S,(Clr M)
Casting Time: 1 round
Range: 30 ft. radius
Target: Self
Duration: Concentration, up to 1 turn
Saving Throw: None
Magic Resistance: No 

When the detect magic spell is cast, the caster detects the presence and location of all magical items, creatures, places and effects around them to a range of 30 feet. Those that can be seen will appear  to the caster to glow with a faint light. The amount of information revealed depends on how long you study a particular area or subject: 

1st Round: Presence and location of each magical aura. 

Subsequent rounds: The caster can determine the strength and school of one magical aura within range.  It takes 1 round to determine an aura's strength, and another to determine its school. 

Magical areas, multiple types of magic, or strong local magical emanations may distort or conceal weaker auras. Extraplanar creatures are not magical in themselves, but if they are summoned, the conjuration spell registers. 

Aura Strength: An aura’s power depends on a spell’s functioning spell level or an item’s caster level. If an aura falls into more than one category, detect magic indicates the stronger of the two. 

Strength	Functioning Spell (Spell Level)	Magic Item (Caster Level)
Faint	3rd or lower	1st-5th
Moderate	4th-6th	6th-11th
Strong	7th-9th	12th-20th
Overwhelming	10th+ (deity level)	21st+ (artifact)

Lingering Aura: A magical aura lingers after its original source dissipates (in the case of a spell) or is destroyed (in the case of a magic item). If detect magic is cast and directed at such a location, the spell indicates an aura strength of dim (even weaker than a faint aura).  How long the aura lingers at this dim level depends on its original power. 

Original Strength	Duration of Lingering Aura
Faint	1d6 rounds
Moderate	1d6 turns
Strong	1d6 hours
Overwhelming	1d6 days

The spell can penetrate barriers, but it is blocked by 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt. 

Detect magic can be made permanent with a permanency spell. 

Components: When cast by a cleric, this spell requires the use of a holy symbol.

The above version is for the Nth Edition emulation of AD&D and Modern D&D.  For Origjnal and Basic, it will be as below.

Detect Magic
Divination
Level: Cleric 1, Magic-User 1
Components: V,S,(Clr M)
Casting Time: 1 round
Range: 30 ft. radius
Target: Self
Duration: Concentration, up to 1 turn
Saving Throw: None
Magic Resistance: No 

When the detect magic spell is cast, the caster detects the presence and location of all magical items, creatures, places and effects around them to a range of 30 feet. Those that can be seen will appear  to the caster to glow with a faint light.

Magical areas, multiple types of magic, or strong local magical emanations may distort or conceal weaker auras. Extraplanar creatures are not magical in themselves, but if they are summoned, the conjuration spell registers. 

The spell can penetrate barriers, but it is blocked by 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt. 

Components: When cast by a cleric, this spell requires the use of a holy symbol.

Perusals & Progressions: Detect Evil

Before I begin, I'll note here for anyone interested that I made a quick edit to the post on cure light wounds.  I decided to keep its ability to cure paralysis, as I had a look at remove paralysis and saw that it affects multiple targets.  The cure wounds spells being able to un-paralyse one person is a reasonable application that doesn't make remove paralysis worthless.

Anyway, on to detect evil.  I think it's safe to say that this has always been a problem spell for D&D.  I feel like its original intent was to detect supernatural evil, like evil spells and people who are possessed, that sort of thing.  Somewhere along the way it became an all-purpose bad person detector, and a crutch for low-level parties to solve mysteries.  (To be honest, the paladin ability is more problematic than the spell, being at-will, but the principle is the same.)  I could be wrong about the above, but part of the purpose of this series is for me to fully explore the origins and development of each spell. It's good to go to the source, and explode any misconceptions I might have.

Alright, let's start with detect evil.

ORIGINAL D&D (1974)

Detect Evil: A spell to detect evil thought or intent in any creature or evilly enchanted object. Note that poison, for example, is neither good nor evil.

Duration: 2 turns. Range: 6".

This spell already starts off ambiguous, with its detection of "evil thought or intent".   I wonder if this ambiguity was a result of there being no specifically evil alignment in OD&D?  Anyway, to me it seems like the intention is that the spell will tell you if somebody or something means you harm.  The  above spell is the magic-user version, and a 2nd level spell; the cleric version is 1st level, and has a duration of 6 turns and a range of 12".  It's also reversed for Chaotic clerics, with no explanation of what that means.

HOLMES BASIC (1977)

Detect Evil — Level 2; Range: 60 feet; Duration: 2 turns

A spell to detect evil thought or evil intent in any creature or evilly enchanted object. Poison, however, is neither good nor evil.

Holmes Basic doesn't change anything up here, except to convert 6" to 60 feet.  The cleric spell has a range of 120 feet and a duration of 6 turns.  The reverse of the spell is named as detect good, but that name is all that's given.

B/X (1981)

Detect Evil
Range: 60'
Duration: 2 turns 

This spell can be used to detect evil intentions, or evilly enchanted objects within 60' causing the creatures or objects to glow. Actual thoughts are not detected; only the "feeling of evil". The exact definition of "evil" is left to each referee, and players should discuss this point so that all are in agreement; "Chaotic" is not always "evil". Poison and physical traps are neither good nor evil.

Now the ambiguity intensifies, as the definition of evil is being specifically left up to the DM.  The advice to discuss it with players is a sound one, but we're already off into the weeds with this spell.  The clarification that it doesn't detect actual thoughts is a good one though.  The cleric spell has the same increased range and duration, but is no longer reversible for some reason.  I suppose when a spell is reversed to detect "good intentions" it's not so useful.  The bit about the affected creatures glowing is an odd one as well.  Is this a glow that everyone can see, or just the caster?

BECMI (1983)

Detect Evil
Range: 60'
Duration: 2 turns
Effect: Everything within 60' 

When this spell is cast, the magic-user will see all evilly enchanted objects within 60' glow. It will also cause creatures that want to harm the magic-user to glow when they are within range. The actual thoughts of the creatures cannot be heard. Remember that "Chaotic" does not automatically mean Evil, although many Chaotic monsters have evil intentions. Traps and poison are neither good nor evil, merely dangerous.

Okay, this is a little better: it specifically detects evilly enchanted objects and creatures that mean the caster harm. Much less ambiguous, and much less likely to cause debates about the nature of evil.  It even clarifies the glowing as something only the caster can see.  As in previous editions, the cleric spell is better.

RULES CYCLOPEDIA (1991)

Detect Evil
Range: 60'
Duration: 2 turns
Effect: Everything within 60' 

When this spell is cast, the spellcaster will see a glow surround all evilly-enchanted objects within 60'. It will also cause creatures that want to harm the spellcaster to glow when they are within range. The spell, however, does not allow the spellcaster to hear the actual thoughts of the creatures.  Remember that Chaotic alignment is not automatically the same as evil, although many Chaotic monsters have evil intentions. Traps and poison are neither good nor evil, but merely dangerous.

The Rules Cyclopedia follows BECMI's lead, without making any changes.  The Basic line, as usual, has done a pretty good job of taking the OD&D spell and refining it, and in this case ironing out most of the ambiguities along the way.

AD&D 1st EDITION (1978)

Detect Evil (Divination) Reversible
Level: 1
Range: 12“
Duration: 1 turn + ½ turn/level
Area of Effect:  1" path
Components: V, S, M
Casting Time: 1 round
Saving Throw: None 

Explanation/Description: This is a spell which discovers emanations of evil, or of good in the case of the reverse spell, from any creature or object. For example, evil alignment or an evilly cursed object will radiate evil, but a hidden trap or an unintelligent viper will not. The duration of a detect evil (or detect good) spell is 1 turn + ½ turn (5 rounds, or 5 minutes) per level of the cleric. Thus a cleric of 1st level of experience can cast a spell with a 1½ turn duration, at 2nd level a 2 turn duration, 2½  at 3rd, etc. The spell has a path of detection 1” wide in the direction in which the cleric is facing. It requires the use of the cleric’s holy (or unholy) symbol as its material component, with the cleric holding it before him or her.

That's the cleric spell above; the magic-user spell is 2nd level, has a 6" range, a duration of 5 rounds/level, a casting time of 2, and doesn't require any material components.  This is where the spell starts to detect actual alignment, and note that nothing is mentioned here about "evil intent".  This is an alignment detector, plain and simple.  It also has a much narrower focus, a 1" path rather than the 60' radius of the Basic version.

AD&D 2nd EDITION (1989)

Detect Evil (Divination)
Reversible 

Sphere: All
Range: 120 yards
Components: V, S, M
Duration: 1 turn + 5 rounds/level
Casting Time: 1 round
Area of Effect: 10-foot path
Saving Throw: None 

This spell discovers emanations of evil, or of good in the case of the reverse spell, from any creature, object, or area. Character alignment, however, is revealed only under unusual circumstances: characters who are strongly aligned, who do not stray from their faith, and who are of at least 9th level might radiate good or evil if intent upon appropriate actions. Powerful monsters, such as rakshasas or ki-rin, send forth emanations of evil or good, even if polymorphed.  Aligned undead radiate evil, for it is this power and negative force that enable them to continue existing. An evilly cursed object or unholy water radiates evil, but a hidden trap or an unintelligent viper does not. 

The degree of evil (faint, moderate, strong, overwhelming) and possibly its general nature (expectant, malignant, gloating, etc.) can be noted. If the evil is overwhelming, the priest has a 10% chance per level of detecting its general bent (lawful, neutral, chaotic). The duration of a detect evil (or detect good) spell is one turn plus five rounds per level of the priest. Thus a priest of 1st experience level can cast a spell with a 15-round duration, at 2nd level he can cast a 20-round duration spell, etc. The spell has a path of detection 10 feet wide in the direction in which the priest is facing. The priest
must concentrate - stop, have quiet, and intently seek to detect the aura - for at least one round to receive a reading. 

The spell requires the use of the priest's holy symbol as its material component, with the priest holding it before him.

The magic-user spell has the same differences as in 1e.  2nd edition walks back the pure alignment detection of 1e, going back to detecting "intent".  It even makes the spell completely unusable on characters of less than 9th level; there's definitely no solving low-level mysteries with this version.  I like the specification of different types of monsters that register.  The introduction of degrees of evil being detected is a little half-baked though, with no indication of how to judge it.  As for the difference between expectant and malignant evil, your guess is as good as mine.

Oh, I just noticed that the range is way high here.  The Basic line converted OD&D's ranges of 6" and 12" into tens of feet, but 2e has gone with tens of yards.  I know that movement rates and missile fire ranges are supposed to be converted into yards in the wilderness in AD&D, but does the same apply to spell ranges?  I've always been iffy on that.  It does seem like an absurdly long range to me.

AD&D 2nd EDITION REVISED (1995)

There aren't any significant changes here.

D&D 3rd EDITION (2000)

Detect Evil
Divination
Level: Clr 1, Rgr 2
Components: V, S, DF
Casting Time: 1 action
Range: 60 ft.
Area: Quarter circle emanating from you to the extreme of the range
Duration: Concentration, up to 10 minutes/level (D)
Saving Throw: None
Spell Resistance: No 

You can sense the presence of evil. The amount of information revealed depends on how long you study a particular area or subject: 

1st Round: Presence or absence of evil. 

2nd Round: Number of evil auras (creatures, objects, or spells) in the area and the strength of the strongest evil aura present. If you are of good alignment, the strongest evil aura’s strength is "overwhelming" (see below), and the strength is at least twice your character level, you are stunned for 1 round and the spell ends. While you are stunned, you can’t act, you lose any Dexterity bonus to AC, and attackers gain +2 bonuses to attack you. 

3rd Round: The strength and location of each aura. If an aura is outside your line of sight, then you discern its direction but not its exact location. 

Aura Strength: An aura’s evil power and strength depend on the type of evil creature or object that you’re detecting and its HD, caster level, or (in the case of a cleric) class level. 

Creature/Object	Evil Power
Evil creature	HD / 5
Undead creature	HD / 2
Evil elemental	HD / 2
Evil magic item or spell	Caster level / 2
Evil outsider	HD
Cleric of an evil deity	Level

Evil Power	Aura Strength
Lingering	Dim
1 or less	Faint
2–4	Moderate
5–10	Strong
11+	Overwhelming

If an aura falls into more than one strength category, the spell indicates the stronger of the two. 

Length Aura Lingers: How long the aura lingers depends on its original strength: 

Original Strength	Duration
Faint	1d6 minutes
Moderate	1d6 x 10 minutes
Strong	1d6 hours
Overwhelming	1d6 days

Remember that animals, traps, poisons, and other potential perils are not evil; this
spell does not detect them. 

Note: Each round, you can turn to detect things in a new area. The spell can penetrate barriers, but 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt blocks it.

Well, 3rd edition certainly took the "degrees of evil" bit from 2e and ran with it.  And we're back to the spell being an alignment detector, with no hint of "evil intent" being a factor.  In a big departure, the spell can't even be cast by wizards anymore, and the area has widened from a 10' line to a quarter circle.  The range is back to feet, not yards.

D&D 3.5th EDITION (2003)

Only two rules changes are made in 3.5 that I can see: the spell is no longer available to rangers, and the numbers have been tweaked for how long evil auras linger.  The tables for determining aura strength have been combined and greatly simplified in presentation, though.  I can't be bothered doing the formatting right now, so I'll just link to the d20 SRD if you want to check it out.

D&D 4th EDITION (2008)

I'm not entirely sure about this, but it looks to me as though this ability doesn't exist in any form in 4e.  I can't say I blame them for getting rid of it.

D&D 5th EDITION (2014)

DETECT EVIL AND GOOD
1st-level divination 

Casting Time: 1 action
Range: Self
Components: V, S
Duration: Concentration, up to 10 minutes 

For the duration, you know if there is an aberration, celestial, elemental, fey, fiend, or undead within 30 feet of you, as well as where the creature is located. Similarly, you know if there is a place or object within 30 feet of you that has been magically consecrated or desecrated. 

The spell can penetrate most barriers, but it is blocked by 1 fool of stone, 1 inch of common metal, a thin sheet of lead, or'3 feet of wood or dirt.

The more I look at 5th edition spells, the more impressed I am by how much they cut away the bullshit.  This spell isn't really detect evil though, at least not in any form it's had previously.  It's not an alignment detector, and it's not an "evil intent" detector, but rather a spell to detect undead and extraplanar creatures.  4e ditched the original, and 5e brought it back in name only.

Nth EDITION

Okay, so the first question I need to answer is this: what does this spell actually do?  I'm going to start with the 3e version as a base, which means it detects evil as an alignment, but I don't want it to detect just regular folks.  For the most part, it's going to work on outsiders, undead, and high-level clerics.  For regular people, humanoids, etc, it will only register faint evil for those who specifically want to harm the caster.  I feel like that covers pretty much all the uses of the spell outlined above.

As in earlier editions, this will be a 1st level spell for clerics, and a 2nd level spell for magic-users.  I'm only developing the game elements from OD&D at the moment, so I don't need to do anything for other classes yet.  I won't bother with the better range and duration for clerics: I figure that getting it as a 1st-level spell is bonus enough.

For the area of effect, I'm going with the 10 foot line rather than the cone, or the radius effect.  I prefer this spell to be as tightly focused as possible.

I thought about ditching the lingering aura stuff, but I kind of like it as a possible tracking method.  It's an extra complication, but it's the sort of thing that's not going to come up very often.

I've also simplified the whole bit about good clerics being stunned by overwhelming auras.  3e uses a formula to figure it out, but I've just boiled it down to a saving throw.  Seems easier that way.

The advanced version of the spell will look like this:

Detect Evil / Detect Good
Divination
Level: Cleric 1, Magic-User 2
Components: V, S, (Cleric M)
Casting Time: 1 round
Range: 60 ft.
Area: 10 ft. wide, 60 ft. long
Duration: Concentration, up to 10 minutes (D)
Saving Throw: None
Magic Resistance: No

You can sense the presence of supernatural evil, and evil creatures that wish you harm. The amount of information revealed depends on how long you study a particular area or subject:

1st Round: Presence or absence of evil. The following are detected: evil creatures that wish you harm; evil undead; evil extraplanar creatures; evil magic items or spells; high-level evil clerics (see below).

2nd Round: Number of evil auras (creatures, objects, or spells) in the area and the power of the most potent evil aura present. If you are of good alignment, and the strongest evil aura’s power is overwhelming (see below), you must make a Wisdom saving throw (DC equal to the HD or caster level) or be stunned for 1 round.  This ends the detect evil spell.

3rd Round: The power and location of each aura.

Aura Power: An aura’s power depends on the type of evil creature or object that you’re detecting and its HD, caster level, or (in the case of a cleric) class level; see the accompanying table.

If an aura falls into more than one strength category, the spell indicates the stronger of the two.

Creature/Object	Faint	Moderate	Strong	Overwhelming
Evil creatures that wish the caster harm	All	-	-	-
Undead and extraplanar (HD)	1-2	3-6	7-12	13 or higher
Cleric of an evil deity* (class levels)	-	7-8	9-12	13 or higher
Evil magic item or spell (caster level)	1-2	3-8	9-12	13 or higher

* Note that clerics of evil deities don't radiate an evil alignment until they gain the ability to cast 4th level spells (usually when they are 7th level)

Lingering Aura: An evil aura lingers after its original source dissipates (in the case of a spell) or is destroyed (on the case of a creature or magic item).  If detect evil is cast and directed at such a location, the spell indicates an aura strength of dim (even weaker than a faint aura). How long the aura lingers at this dim level depends on its original power. Note that creatures who only register because they wish the caster harm leave no lingering aura.

Original Power	Duration of Lingering Aura
Faint	1d6 rounds
Moderate	1d6 minutes
Strong	1d6 hours
Overwhelming	1d6 days

Animals, traps, poisons, and other potential perils are not evil, and as such this spell does not detect them.

Each round, you can turn to detect evil in a new area. The spell can penetrate barriers, but 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt blocks it.

This spell is reversed as detect good.  It works exactly as detect evil, but detects creatures and magic of good alignment. 

Components: A cleric requires their holy symbol to cast this spell.

For the simpler version of the spell for OD&D and Basic, I've stripped out the lingering auras and the stuff about aura power, as shown below.  I also switch the alignment detection from evil to chaotic, as the Basic line has no evil alignment.  In those games, chaotic pretty much equates to evil so it should work.

Detect Evil
Divination
Level: Cleric 1, Magic-User 2
Components: V, S, (Cleric M)
Casting Time: 1 round
Range: 60 ft.
Area: 10 ft. wide, 60 ft. long
Duration: Concentration, up to 10 minutes (D)
Saving Throw: None
Magic Resistance: No

You can sense the presence of supernatural evil, and evil creatures that wish you harm. The amount of information revealed depends on how long you study a particular area or subject:

1st Round: Presence or absence of evil. The following are detected: chaotic creatures that wish you harm; chaotic undead; chaotic extraplanar creatures; chaotic magic items or spells; high-level chaotic clerics (those capable of casting 4th-level spells).

2nd Round: Number of evil auras (creatures, objects, or spells) in the area. If you are of lawful alignment, and the Hit Dice or caster level of the strongest aura is 13 or more, you must make a Wisdom saving throw (DC equal to the HD or caster level) or be stunned for 1 round.  This ends the detect evil spell.

3rd Round: The location of each aura.

Animals, traps, poisons, and other potential perils are not evil, and as such this spell does not detect them.

Each round, you can turn to detect evil in a new area. The spell can penetrate barriers, but 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt blocks it. 

This spell is reversed as detect good.  It works exactly as detect evil, but detects creatures and magic of lawful alignment.  

Components: A cleric requires their holy symbol to cast this spell.

NEXT: Next time (probably Monday) I'll be looking at detect magic.

AD&D Players Handbook part 53: 7th-Level Illusionist Spells

There are six spells of 7th level for illusionists in AD&D, the same number as in OD&D.  The only difference is that maze has been replaced by first level magic-user spells.

Alter Reality: This spell is similar to limited wish, meaning that it can accomplish pretty much anything the caster desires, albeit partially or with a limited duration.  The major difference is that the illusionist must first visualise the effect they want with a phantasmal force.  (I assume this requires a separate casting of that spell, and isn't included as part of alter reality.)
  The OD&D spell is the same, although it only requires the casting of an illusion, not phantasmal force specifically.

Astral Spell: Like the 7th level cleric spell, this allows the caster to project into the Astral Plane, and from there enter the Outer Planes.  Check out this earlier post for my thoughts on the cleric version of the spell, and how it interacts with Gygax's previous writings on the planes.
  The OD&D spell seems to have been intended to allow the caster to explore the material plane in an astral form, rather than granting travel to other planes.  It doesn't mention the planes at all, as the spell was created before Gary had published his ideas about D&D cosmology.

Prismatic Spray: The caster fires seven rays, each of a different color and effect.  The ray that strikes the target is determined randomly, and it's possible that multiple rays may strike the target.  The various effects refer back to prismatic sphere, which I'll recap here: red - inflicts 10 damage; orange - inflicts 20 damage; yellow - inflicts 40 damage; green - save vs. poison or die; blue - save vs. petrification or turned to stone; indigo - save vs wand or driven insane; violet - save vs. magic or sent to another plane.
  Prismatic spray was mentioned in OD&D, as a new spell in an article from The Dragon #1.  But although it was in the list of new spells, it didn't actually get a proper description.  This is the first time that the spell has been given concrete rules.

Prismatic Wall: This spell is also similar to prismatic sphere, but it creates a wall that is 4' wide per caster level, and 2' high per level.  Anyone passing through is subject to all of the effects listed above under prismatic spray.  Each colour can be dispelled with a specific spell.
  In OD&D, the red, orange and yellow colours did slightly more damage.  The indigo colour turned creatures into crystal rather than driving them insane.  And the violet colour drive characters insane rather than sending them to another plane.

Vision: The caster contacts some sort of supernatural enemy, and asks a question which may be answered with a vision.  The result of this contact is determined randomly.  A high roll results in a useful vision, a medium roll results in a vision that may or may not be relevant, and a low roll results in the entity being annoyed and hitting the caster with a geas or quest.  The material component is the sacrifice of something important to the caster or the entity, and something very precious will grant a bonus to the roll.
  The OD&D spell doesn't specifically say that the reply comes in a vision.  It uses the NPC Reaction Tables to determine the result, but it is otherwise the same.  There's no mention of material components, though.

First-Level Magic-User Spells: Instead of gaining a 7th-level spell, the caster gains a number of 1st-level magic-user spells.  The list of spells to choose from isn't complete: dancing lights, detect magic, find familiar, identify, jump, light, push, spider climb, ventriloquism and write aren't included.  The illusionist gains four spells at 14th level, and an additional one per level above that - presumably this isn't set in stone when the spell is cast, and the caster keeps gaining m-u spells as they level up.  They don't get the spells automatically, though - they must seek them out like a magic-user.  To my mind this seems weak for a 7th-level spell, but I suppose it does give the illusionist a little more utility.  And magic missile is a pretty good spell even at high levels.
  The OD&D version of the spell was 4th level, and allowed the illusionist the use of every 1st-level magic-user spell.  No doubt Gary decided that this was too powerful, and pulled it back.  There was also a 5th-level spell that granted the use of all 2nd-level magic-user spells, but that was completely gotten rid of.

Some illusionist end-notes: So that's the end of the illusionist spell list, and the end of the PHB spells entirely.  Going back over my notes, I was reminded that the Illusionist spell list was rolled out in a piecemeal fashion.  The class was introduced by Peter Aronson in The Strategic Review #4, which gave spells up to 5th level.  For the most part they all made the transition, aside from the aforementioned 2nd-level magic-user spells.  Another article by Aronson in The Dragon #1 brought in spell levels 6 and 7, as well as introducing some more lower level spells.  Again, these made the cut for AD&D mostly unscathed.
  There was a third article about illusionists by Rafael Ovalle in The Dragon #12, which brought in a lot of extra details about illusionists and introduced a load of new spells.  None of these made it into the PHB, possibly because they were published too late.  Whatever the reason, it seems like they faded into obscurity.  I'll still have them in my Ultimate Sandbox campaign, but as spells that can be discovered in old tomes and scrolls rather than ones on the default spell list.

AD&D Players Handbook part 52: 6th-Level Illusionist Spells

There are 8 spells of 6th level for illusionists in AD&D, up from 6 in OD&D.  Shadow Monsters III has been renamed to shades, demi-shadow magic has been brought up from 5th level, and veil is brand new.

Conjure Animals: Like the 6th-level cleric spell, it allows the caster to summon a number of animals whose total Hit Dice are equal to the level of the caster.  It has a duration of 1 round/level (vs. 2 rounds/level for clerics) and a casting time of 6 segments (vs. 9 for clerics.)  I find the actual conjuring of for-real creatures somewhat of an odd fit for illusionists.  Doesn't it go against the theme a bit?  I suppose stage magicians are always pulling animals out of things though, so maybe it's fine.
  The OD&D version of the spell wasn't limited by Hit Dice.  It allowed the caster to summon one creature the size of an elephant, three the size of bears, or six the size of wolves.

Demi-Shadow Magic: The spell works like shadow magic (detailed in my last post), but it also allows the illusionist to cast quasi-real versions of wall of fire, wall of ice or cloudkill.  As with shadow magic, the spells function as though real to anyone who fails their saving throw.  Against anyone who makes it, the damage is reduced, and in the case of cloudkill it will only kill creatures with less than 2 Hit Dice.  It can still be used to cast the same spells as shadow magic, but they now deal 2 points of damage per level instead of 1 against those who make their save.
  The OD&D version of the spell was the same in that it dealt more damage then the weaker version of the spell.  It didn't allow for the casting of magic missile, cone of cold, or cloudkill.  The original spell allowed the casting of death spell, which seems to have been replaced by cloudkill.

Mass Suggestion: This works like the suggestion spell, but it affects one creature per level, as long as they're all within 3" of the caster.  Every target is under the same suggestion.  If cast on a single target, there's a penalty to their saving throw.
  The OD&D spell was the same, but it affected 1d8 targets rather than one per level.

Permanent Illusion: Like spectral force, it creates an illusion of a creature or object with visual, sound, smell, and thermal elements.  The main difference is that the illusion is permanent, requiring no concentration from the caster.
  The OD&D spell was exactly the same.

Programmed Illusion: This spell sets up a spectral force that is triggered by certain conditions, and last for 1 round/level.
  The OD&D spell had a flat duration of 12 turns, rather than 1 round/level.

Shades: Similar to shadow monsters and demi-shadow monsters, but the creatures created are 60% real.
  In OD&D this spell was called shadow monsters III.  It granted creatures a base AC of 7 (whereas the AD&D spell remains at AC 10), and allowed the creation of a total Hit Dice equal to double the illusionist's level (in AD&D it still remains equal to the caster's level).

True Sight: Like the 5th-level cleric spell (called true seeing), it allows the caster to everything within range in its true form, regardless of illusions, polymorphs, and other forms of disguise.  Unlike the cleric spell, the illusionist isn't able to discern alignment.  The illusionist spell has a range of 6" (vs. 12" for clerics) and a casting time of 1 round (vs. 8 segments).  Illusionists don't require any material components.
  The OD&D spell allowed the caster to discern alignment, class, level and the intentions of any target.  I'm not surprised that Gary jettisoned all of that.  It also had a complicated duration formula of the character's level minus 10, + 1d6 rounds.  In AD&D it's a simple 1 round/level.

Veil: The caster is able to change the visuals of their surroundings and/or their party.  These illusions can be touched without disappearing, and will only be penetrated by true seeing, a gem of seeing, or the like.

As you may have noticed, I'm powering through these entries as quickly as possible.  I started detailing these spells all the way back in 2016, and once I got started I felt obligated to see it the whole way through, regardless of how tedious it got.  Well, the end is quite literally in sight: I'm finally at a page in my PHB where the spell entries are done.  For those of you who followed me through this, thank you.  It should be quite a while before I do something like this again: I'm thinking it'll be when I hit the Moldvay Basic Set, and obviously that won't be anywhere near as long.  Regardless, I'm glad to be almost done.  It can only get more interesting from here.

AD&D Players Handbook part 51: 5th-Level Illusionist Spells

There are 8 spells of 5th-level for illusionists in AD&D, the same number as in OD&D.  The lists are a bit different, though.  The spells create spectres and 2nd level magic-user spells have both been dumped entirely.  Shadow magic is now 5th-level, whereas it was 4th in OD&D.  This means that demi-shadow magic has been bumped up from 5th to 6th.  Maze has been added in from the magic-user list, and shadow door is brand new.

Chaos: This is a variant of the 7th-level druid spell confusion, but instead of affecting 2-8 creatures it affects everyone within an area of up to 4" x 4".  The only creatures that get saving throws against this spell are straight fighters (not paladins or rangers), illusionists, and monsters with no magic and an Intelligence of 4 or less.  If I'm reading this spell correctly, it's incredibly powerful; you could take multiple high-level foes out of a fight unless they have magic resistance.  Going through this list is making me begin to realise why some 1e players love the illusionist.
  The OD&D spell only affected a 3" x 3" area.  It only gave a saving throw to high-level fighters and illusionists, whereas AD&D makes no such distinction.  It also lasted for as long as the illusionist maintained concentration, whereas AD&D changes it to 1 round/level. The range has also been changed from a flat 12" to 1/2" per round.

Demi-Shadow Monsters: This spell works exactly like shadow monsters (detailed in my last post), but instead of being 20% real the monsters created are 40% real, with an AC of 8.
  The only difference from the OD&D version is that the original spell allowed the caster to summon 1.5 times their level in total monster Hit Dice.  The AD&D spell keeps it to 1 level per Hit Die, the same as shadow monsters.

Major Creation: This spell is like minor creation (detailed in my last post), but it can also create mineral objects, things made from metals and stone.  These will last for 6 turns/level, and any vegetable-based items created last for double that.
  Again, as with  minor creation, the items created by this spell in OD&D were limited by weight rather than volume.  It also said that the caster gets "full djinni creation powers", which is a lot stronger than the AD&D spell, as it gives any vegetable matter created a permanent duration.  Metal items created were limited in duration based on the hardness of the metal, with gold lasting a day.

Maze: Like the 8th-level magic-user spell, it traps the target in an extra-dimensional maze.  The only difference between the two spells is that the illusionist spell has a casting time of 5 segments, whereas magic-users take 3 segments.  It has no saving throw, but a duration based on the target's intelligence.
  The OD&D spell had only minor differences in duration.  It also didn't mention that Minotaurs are immune to it.

Projected Image: Like the 6th-level magic-user spell (called project image), it creates an illusion of the caster that can be used to cast spells.  It has a range of 1/2" per level (1"/level for an m-u), and a casting time of 5 segments (1 turn for an m-u).  For some reason, the illusionist spell gives no duration at all, which I would assume is a mistake.  The magic-user spell has a duration of 1 round/level.
  The OD&D spell had a flat range of 24" and a duration of 6 turns.  It also didn't mention anything about the image being immune to damage, or specifically vulnerable to dispel magic.  It was otherwise the same as in AD&D.

Shadow Door: This spell creates an illusory door.  If the illusionist steps through, he turns invisible and can flee.  (No word on whether this spell functions like regular invisibility or improved invisibility).  Anyone else who looks through or enters this door will find a 10' x 10' room, and only a true seeing spell or a gem of seeing will reveal the truth.

Shadow Magic: The caster can cast quasi-real versions of the following spells: magic missile, fireball, lightning bolt or cone of cold.  It will deal regular damage on someone who fails their save, but against anyone who makes the save it deals 1 hp/level.
  The OD&D spell was similar, but it allowed the following spells instead: lightning bolt, fireball, wall of fire, wall of ice, and death spell.  As in AD&D, these spells were fully effective against those who made a saving throw.  Against others they dealt reduced damage, and the death spell would kill 1d8 1st-level creatures.

Summon Shadow: Summons one shadow for every 3 levels of the caster, fully under their control.  The material component is a bit of smoky quartz.
  The OD&D spell summoned one shadow for every level of the caster over 5th, so this spell has been significantly nerfed.

AD&D Players Handbook part 50: 4th-Level Illusionist Spells

There are 8 spells of 4th level for Illusionists in AD&D, the same number as they had in OD&D.  Two of the spells on the AD&D list were 3rd level in OD&D: phantasmal killer and dispel exhaustion.  They replace shadow magic (which gets bumped to 5th level) and 1st-level magic-user spells, which is bumped up all the way to 7th level.

Confusion: Like the 4th-level magic-user spell and the 7th-level druid spell, it causes all those affected within the area to act at random, as determined by rolling on a table.  It has a range of 8" (vs. 12" for magic-users), a duration of 1 round/level (magic-users get the same, with 1 round extra), and an area of 4"x4" (vs. 6"x6" for an m-u).  Illusionists have the same parameters for this spell as druids (except for a casting time of 4 segments, vs. 9 for druids).
  The OD&D spell gave no saving throw for creatures under 4 Hit Dice, where as this version has no such power.  It also had a delayed effect on any creature over 2 HD; again, that's not present in the AD&D spell.

Dispel Exhaustion: This spell restores 50% of a target's hit points, affecting up to 4 creatures touched by the caster in a single round.  It also allows a target to move at double speed for 1 round per turn.  This effect is illusory, and when the spell ends the targets all drop back to the hp total they had before (modified, one assumes, by any damage taken in the interim).  The spell has a lengthy duration, though, so it's actually worth using in lieu of genuine healing.
  This spell was 3rd-level in OD&D.  It didn't mention restoring hit points specifically.  Instead it "allowed action without rest", but after the spell the recipient had to rest for twice the amount that they missed.  It allowed those recently raised from the dead to act normally, as well as those badly wounded, but they took 1d6 damage while doing so.  It had a flat duration of 4 hours, whereas in AD&D the spell lasts for 3 turns/level.

Emotion: Causes all creatures within a 4" x 4" area to react with one of four emotional effects.  Fear causes them to panic and flee, like the fear spell, but the targets suffer a -2 penalty to their saves.  Hate grants the recipients +2 to morale, saving throws, attack rolls and damage.  Hopelessness makes its targets utterly dejected. They will turn back from any task, submit to any demands, and have a 25% chance of doing nothing at all in any round.  Rage drives the recipients berserk, giving them +1 to hit, +3 to damage, and +5 to hit points, but causing them to fight with no regard for their own safety.  Fear and rage counter each other, and the same goes for hate/hopelessness.
  The OD&D spell was the same in principle, but its practical effects were completely different.  Fear was much the same, mimicking the OD&D version of that spell.  Battle lust was the equivalent of rage, but its mechanical effects weren't quite so extensive.  It simply allowed the recipient to fight as a Berserker, granting them +2 to attack and and making them immune to morale checks.  (I suppose it could have been referring to the Berserker class from Dragon magazine, which would grant more extensive benefits.)  Fear could counter battle-lust, but not vice-versa.  Deprivation was the equivalent of hopelessness.  Bravado granted immunity to fear, and could counter deprivation.  Hate didn't grant any bonuses. Instead it made the victim attack a random target, as rolled on a chart.  There was even a result for "hate self", meaning that they would commit suicide.  It's not hard to see why Gary tweaked that.  Also, the OD&D spell never specifies how many targets or what area it can effect.  It's completely open to interpretation.

Improved Invisibility: This spell works like invisibility, except the target can make attacks and cast spells without reappearing.  They can be detected by a tell-tale shimmer, but all attacks against them suffer a penalty, and they gain a bonus on all saving throws.
  In OD&D, the spell was said to be the same as Invisibility 10' Radius, which would have meant that it could affect numerous targets instead of the single target of the AD&D spell.

Massmorph: Like the 4th-level magic-user spell, it gives a number of creatures the appearance of a copse of trees.  Unlike the m-u spell it requires no material components, and only takes 4 segments to cast (magic-users take a full turn).  It affects a 1" x 1" area.  Weirdly, the magic-user spell affects an area of 11' x 1".  It's a very odd measurement for a D&D spell, and I wonder if there's perhaps a typo.
  The major difference from the OD&D version of the spell is that in OD&D it affected a flat 100 man-sized creatures.  The AD&D spell affects 10 per level.

Minor Creation: The caster can create a non-living, organic object of 1 cubic foot per level in volume.  This generally means things made out of wood, ropes, and "soft goods", which apparently means cloth and fabric.  The items last for an hour per level.  Material component is a small piece of the same kind of object being created.
  The OD&D spell creates the same kinds of materials, but is limited by weight rather than volume.  It also has a duration measures in days rather than hours, with a nebulous bonus or penalty to be applied by the DM based on the hardness of the item created.

Phantasmal Killer: This spell creates an image in the target's mind of the most horrible creature that their subconscious can dredge up.  This image attacks as a 4 Hit Dice creature, and if it strikes a blow the target will die from fright.  Saving throws against this spell are rolled in a nonstandard manner, being a 3d6 roll under the target's Intelligence (with various situational modifiers applied).  My favourite part is the note about helms of telepathy: not only does wearing one grant a -3 bonus to the roll, but it also allows the target to turn the phantasmal killer back on the caster.
  The OD&D version of this spell was 3rd level, and I can see why they bumped it up.  The spell works almost exactly the same, except that the various modifiers to the saving throw are different.  Having been attacked by this spell previously grants a flat -5 bonus, whereas in AD&D it's -1 per previous attack.  The OD&D spell had a range of 6", as opposed to 1/2" per level in AD&D.

Shadow Monsters: Creates a number of semi-real monsters, whose total combined Hit Dice cannot exceed the level of the caster.  They only have 20% of their usual hit points.  Against any target that fails their saving throw, the monsters defend and deal damage as normal.  Against those that make their save, they will have AC 10 and deal 20% of normal damage.
  The OD&D version of the spell also summoned semi-real monsters, with much the same parameters.  All those monsters had an AC of 9 (the worst possible in OD&D), regardless of whether the targets believed in them or not.  The spell was much more specific about monster special abilities, such as breath weapons and petrification: they only worked on those that believed they were real.  AD&D is a bit vaguer, saying only that they "perform as normal with respect to armor class and attack forms".  Shadow monsters in OD&D took double damage from silver weapons, a weakness not present in AD&D.

AD&D Player's Handbook part 49: 3rd-Level Illusionist spells

There are twelve illusionist spells of 3rd-level in AD&D, the same number as their were in OD&D.  Phantasmal killer was on this list in OD&D, but has been bumped up to 4th level.  Dispel exhaustion has also been bumped up to 4th level.  Replacing them are rope trick and dispel illusion, the latter of which has been bumped up from 2nd level.

Continual Darkness: Like the 2nd-level magic-user spell darkness 15' radius it creates a 3" diameter globe of impenetrable shadow.  It has a flat range of 6" (vs. 1"/level for m-u) and a casting time of 3 segments (vs. 2 for m-u).  The biggest difference is that this version of the spell is permanent in duration.
  In OD&D, this spell was based on the anti-cleric's continual darkness, which was a reversed version of continual light.  That gave it a whopping diameter of 24", which has been greatly nerfed here.

Continual Light: Like the 3rd-level cleric spell, it creates a globe of light that illuminates a 6" radius.  It has a range of 6" (vs. 12" for clerics) and a casting time of 3 segments (6 for clerics).  Both versions are permanent.
  As mentioned above, the biggest difference from the OD&D spell is that the illumination has been greatly reduced from 24".

Dispel Illusion: The caster is able to automatically dispel any phantasmal force created by a non-illusionist.  It can dispel any illusion/phantasm created by an illusionist, with a base 50% chance adjusted up or down depending in the level difference between the two casters.
  In OD&D, this was a 2nd-level spell.  It's able to dispel any illusions cast by a non-illusionist, which is a broader rule and probably a better one; the AD&D version doesn't account for new spells that may be introduced.  Against those of other illusionists it uses the OD&D rules for dispel magic, which was a ratio of the dispeller's level over that of the original caster.

Fear: Like the 4th-level magic-user spell, it causes creatures caught within a conical area to flee in panic.  The only difference is that it doesn't require any material components, and it has a segment time of 3 (vs. 4 for magic-users).
  The OD&D spell worked similarly, but targets had a flat 50% chance to drop what they were carrying, unmodified by level.  The duration was 6 turns, whereas in AD&D targets will run for a number of rounds equal to the caster's level.  The spell had a range of 24", while the AD&D spell only goes to 6".  The OD&D spell functioned like the fear wand, though, so it's still a 6" cone.  Does this mean that OD&D casters could designate the beginning of the cone anywhere within 24"?  It feels a little odd, but I guess it's not that different from lightning bolt.  The AD&D spell almost certainly originates from the caster.  (Yeah, I did a a cut-and-paste from when I covered the magic-user version.  I have a life to live, and I'd do it again in a heartbeat.)

Hallucinatory Terrain: Like the 4th-level magic-user spell, it can changes the appearance of terrain in a 4"x4" area (with 1" added to both dimensions per level).  The magic-user spell was a flat 1" square per level.  The illusionist version also has a 2" bonus to range over the magic-user version.  The illusionist spell has a casting time of 5 segments (vs. 1 turn for magic users, which is a lot longer).
  The OD&D spell is similar, if a bit more vaguely worded.  It doesn't have a specific area of effect, it's simply said that it affects a "large area".  It had a range of 24", whereas AD&D has as range of 2" + 2"/level.  (See, I told you I'd do it again.)

Illusionary Script: Gary, the word you're looking for is "illusory".  Anyway, the caster can write something and then make it appear as though it's written in a foreign language.  Only those that the caster designates can read it, with all others being confused for 5-20 turns.  This duration drops by a turn per level of the victim.  Other illusionists can tell that the script is an illusion.  The material component is a lead-based ink that must be specially made by an alchemist.
  The OD&D spell only confused its victims for 1-6 turns, not affected by their level.  It also had a limit of one page of writing, which isn't present in AD&D.

Invisibility, 10' Radius: Like the 3rd-level magic-user spell, it casts an invisibility spell on every creature you want within 10 feet of the original target.  The only difference is that the illusionist spell requires no material components.
  The AD&D spell isn't clear as to whether it grants invisibility to multiple creatures within the area, or if it creates an area of invisibility that moves with a single target.  I've gone with the former option.  The OD&D spell was similarly vague.  It had a range of 24", whereas in AD&D it's a touch spell.

Non-Detection: Makes the caster completely immune to detection spells, ESP, clairaudience, clairvoyance as well as scrying from magic items.  It's a somewhat advanced version of misdirection, although by providing false information the latter spell remains useful.  Its material component is a pinch of diamond dust.
  The OD&D spell worked similarly, although it wasn't as specific about which spells it protected against.  It did specify protection against ESP and crystal balls.  It had a duration of 2 rounds/level, whereas the AD&D spell lasts for 1 turn/level, about five times longer.

Paralyzation: The spell creates an "illusionary muscle slowdown" in its targets, paralyzing them if they fail a saving throw.  It affects a 2" x 2" area, but can only work on a Hit Dice total up to double the caster's level.  A dispel magic or dispel illusion will end the paralysis, or it can be ended by the caster.  Otherwise, it apparently lasts forever.  Harsh.
  The OD&D spell worked the same, although it didn't limit the spell area at all.  It had a range of 18" (vs. 1"/level in AD&D).

Rope Trick: Like the 1st-level magic-user spell, this causes a rope to stand on end, and opens a portal to a pocket dimension at the top.  The only difference is that it takes 3 segments to cast, instead of 2 for magic-users.
  The OD&D spell could work with a shorter rope, but it could only let the caster and three others inside the pocket dimension; the AD&D version allows five others inside.  It had a duration of 6 turns +1/level, whereas AD&D gives it 2 turns/level.

Spectral Force: This spell functions like phantasmal force, but along with the visual element it also includes sound, smell and heat/cold.  It lasts for 3 rounds after the caster stops concentrating on it.
  The OD&D spell was called spectral forces.  It was otherwise similar, with one major difference: it created illusions that could not be destroyed by touching them.  This isn't specified in AD&D.  Also, it lasts for 5 "turns" after concentration, as opposed to AD&D's 3 rounds.

Suggestion: Like the 3rd-level magic-user spell, the caster is able to influence a single target.  The illusionist spell lasts for 4 turns + 4/level, whereas the magic-user version lasted longer at 6 turns + 6/level.
  The only real difference that the OD&D version of the spell had was its duration of one week.

AD&D Player's Handbook part 48: 2nd-Level Illusionist Spells

There are 12 illusionist spells of 2nd level in AD&D, the same number as in OD&D.  The only difference between the two lists is that dispel illusion is now gone, and has been replaced by ventriloquism.  Ventriloquism was a 1st level illusionist spell in OD&D, but now it's been bumped up a level.

Blindness: The target must save vs. spells or be struck blind, permanently.  Healing magic won't fix it: only a dispel magic will work, or the caster removing the effect.
  The OD&D spell was exactly the same, except that it had a range of 12" as opposed to 3" in AD&D.

Blur: The caster's outline becomes blurry, making him more difficult to hit.  The first attack by any foe suffers a -4 penalty, and subsequent attacks are at -2.  It also grants a +1 to saving throws against direct magical attacks.
  The OD&D spell granted a flat -2 penalty on all attacks, and a +2 bonus to saving throws vs. wands and staves.  It had a duration of 4+1d4 rounds, whereas AD&D has one of 3 rounds + 1/level.

Deafness: The spell strikes one target deaf if they fail a saving throw.  As with blindness, the spell is permanent and can only be fixed by dispel magic or the caster's dismissal.
  Again, the only difference between this and the OD&D version is that the original had a range of 12" and the AD&D version has a range of 6".

Detect Magic: This is the same as the 1st-level cleric/magic-user spell, in that it detects magical radiations within the area of effect.  The only difference between the illusionist and magic-user versions is that illusionists cast with a time of 1 segment, as opposed to 2.  The cleric spell takes a full round to cast, and has half the range (3", as opposed to 6" for the others).  The cleric spell lasts for a full turn, whereas the illusionist and m-u versions last for 2 rounds/level.  It also required a holy symbol; the illusionist and m-u spell has no material component.
  The only difference from the OD&D spell is that it had a duration of 2 "turns".  (Could be rounds or turns. You know, typical OD&D ambiguity.)

Fog Cloud: Creates a billowing cloud of fog that moves away from the caster at a rate of 1".  It looks like a cloudkill spell, but it only obscures vision.  For practical purposes, it's probably not as good as the 1st-level spell wall of fog, which covers a larger area when cast by a 2nd level+ caster.  Other than that, I guess it's used to scare enemies who think it's actually a cloudkill?
  The OD&D spell was simply called fog, but it otherwise functioned the same.

Hypnotic Pattern: Creates a pattern of colours in the air.  Up to 24 Hit Dice worth of creatures within the 3"x3" area of effect must make a save or become fascinated.  Such creatures will stand motionless for as long as the caster concentrates on maintaining the pattern.  The material component is a glowing stick of incense or a crystal rod full of phosphorescent material.  All told, this is a very useful spell - anything capable of negating a 24HD creature is pretty good, even if it's not all that likely to fail the saving throw.
  The OD&D spell had the same effect, but rather than a Hit Dice total it affects a number of targets based on their level: 2-24 1st level types, 3-18 2nd-level types, etc.  It tops out with 1-6 5th or 6th-level types.  This is a lot less potentially powerful, if you interpret level here to mean Hit Dice.  If you interpret it as referring to the levels from the Random Encounter Tables, it's a bit closer to the AD&D spell, but what do you do when its cast against monsters that aren't dungeon dwellers?  The OD&D spell lasted for 4-9 rounds after the caster stopped concentrating, whereas in AD&D it stops right away.  The OD&D range is 12", as opposed to a range of 0" in AD&D (AD&D covers this with an area of effect instead of a range).

Improved Phantasmal Force: Like phantasmal force, this spell creates an illusory creature or object that can damage anyone who believes it is real.  It doesn't require as much concentration to maintain, however, as the caster can move at half speed and still concentrate upon it.  It also lasts for 2 rounds after the illusionist stops maintaining it.  Most significantly of all, it can now make sounds, though not intelligible speech.  The silent nature of phantasmal force is probably the thing that most holds back its believability, so this is a pretty big deal.
  The OD&D version of the spell was called improved phantasmal forces, and it gave the caster the ability to move and still maintain the spell.  It also continued after the caster ceased concentration, but it lasted for 3 "turns" extra.  It didn't say anything about making sounds, but then again the OD&D phantasmal forces didn't specify that it was silent.

Invisibility: Just like the 2nd-level magic-user spell, it turns a character invisible until such time as they wish to reappear or make an attack.  The only difference is that it requires no material components.
  The only real difference between the OD&D and AD&D versions of this spell is that OD&D gives it a range of 24", while in AD&D it's a touch-based spell.

Magic Mouth: Like the 2nd-level magic-user spell, it allows the caster to endow an object with a magic mouth that can relay a short message.  The magic-user and illusionist versions of this spell are identical.
  The main difference from the OD&D spell is that it could be triggered based on the alignment of someone nearby, whereas that's expressly forbidden in AD&D.

Mirror Image: This is like the 2nd-lvel magic-user spell, but rather than creating 1-4 images to surround the caster, it creates 1d4+1.  It also has a range of 3" per level, as opposed to 2"/level for magic-users.
  The OD&D spell didn't grant the illusionist an extra image.

Misdirection: The caster places this spell on a creature or object, and any detection spell cast upon it (such as detect evil or detect snares and pits) will return the wrong information.  The caster of the detection spell gets a saving throw to avoid this.
  The OD&D spell was called misdetection, which was more literal but also a little awkward.  It used the same method as dispel magic to gauge its success, which was determined by the difference in level between the two casters.  Using a saving throw is certainly a simpler way to get it done.

Ventriloquism: Like the 1st-level magic-user spell, it allows the caster to make their voice come from somewhere else.  The illusionist version increases the maximum range to 9" (vs. 6" for magic-users) and also increases the duration, to 4 rounds + 1/level (vs. 2 rounds + 1/level).  Illusionists have a casting time of 2 segment, whereas magic-users could cast it in 1.
  The OD&D spell was 1st level for illusionists, but otherwise the same.  It had a flat range of 5".

AD&D Player's Handbook part 47: 1st-Level Illusionist Spells

There are twelve illusionist spells of 1st-level in AD&D, the same number as there were in OD&D.  Two of these spells (audible glamer and dancing lights) are new to the list, replacing ventriloquism and mirror image.

Audible Glamer: Like the 2nd-level magic-user spell, it creates whatever sound the caster desires.  The m-u description says that, when cast at 3rd level, it creates a sound volume equivalent to four men.  Illusionists can cast the spell at 1st level, so I need to figure out if their spell volume begins at four men, or if it starts lower.  I'll probably start them at four, just to make the spell more useful.  The illusionist version of the spell lasts longer (3 rounds/lvl as opposed to 2), is quicker to cast (2 segments as opposed to 5) and requires no material components.

Change Self: The caster is able to change their appearance to that of another man-shaped creature, although they can't make themselves look more than 1 foot taller or shorter.  The illusion can affect their equipment as well.
  The OD&D version of the spell says that the user can appear as a creature of the same general size and shape, which I actually like better.  It makes the spell useful for dragons and other non-humanoid spell-casters.  The duration in OD&D was 10 rounds + caster level + 1d6 rounds.  In AD&D it's 2-12 rounds + 2 rounds/level.  Those durations seem a little needlessly complex, but I suppose it's to inject a little bit of uncertainty as to when the spell's going to end.

Color Spray: This spell creates a cone of clashing colors that affects 1-6 creatures within its area. Creatures with HD equal to or lower than the caster are struck unconscious, those up to 2 HD higher are struck blind, and those 3 or more HD higher are stunned.  Creatures with more HD than the caster has levels receive a saving throw, as do any creatures with more than 6 HD.  Its material components are a pinch of powder or sand colored red, yellow and blue.
  There's a line in the spell that seems contradictory to me: "The spell caster is able to affect 1 level or hit die of creatures for each of his or her levels of experience".  If that's the case, how would the spell affect creatures with more HD than the caster's level, as detailed above?  Is there something I'm missing here?
  The OD&D version might shed some light here.  It affects 1-6 levels of creatures, rather than 1-6 individual creatures, with the number of levels equal to the caster's level.  The target is randomly assigned, with fully affected targets receiving no saving throw and any partially affected one getting a save (with a bonus for every HD unaffected).  The spell couldn't affect creatures with more than 6 HD at all.  It also couldn't blind or stun targets: it always knocked them unconscious.
  I don't know, I can't get that line to make sense.  Perhaps it works like the OD&D spell, only partially affected creatures are blinded or stunned rather then getting a saving throw bonus?  However it works, the OD&D spell was more clearly explained.

Dancing Lights: Works exactly like the 1st-level m-u spell, creating 1-4 balls of light or a glowing, man-shaped figure.

Darkness: Works like the 2nd-level m-u spell darkness 15' radius, creating a globe that light and infravision can't penetrate.  The illusionist version doesn't last as long as the m-u spell (2-8 rounds + 1 round/level, as opposed to 1 turn + 1 round/level) but it's quicker to cast (1 segment vs. 2) and requires no material components.
  The OD&D spell was said to be the same as that cast by "Anti-Clerics," and was defined only as an opposite of light.  That gave it a similar radius of 15", and a duration of 6 turns + 1/level.  That could be a super-long duration, but as ever in OD&D it's hard to say if this was intended to be turns of ten minutes or combat rounds.

Detect Illusion: Allows the caster to know an illusion for what it is, and to allow others to do so with a touch.  Its material component is a piece of yellow crystal, glass or mica.
  The OD&D spell was the same, although it said nothing about bestowing the ability upon others.  It had a range of 6" (1"/level in AD&D) and a duration of 3 "turns" (3 rounds + 2/level in AD&D).

Detect Invisibility: Like the 2nd-level m-u spell, it allows the caster to see invisible, astral, ethereal, hidden, or out of phase creatures and objects to a range of 1"/level.  The illusionist spell is a bit quicker to cast (1 segment vs. 2).
  The OD&D spell was named detect invisible, and detected invisible creatures and objects.  It mentioned nothing about those that are hidden, astral, ethereal or out of phase.  It had a duration of 6 turns (5 rounds/level in AD&D) and a range of 1"/level (same as AD&D).

Gaze Reflection: Creates a mirror-like area around the caster that reflects gaze attacks back upon the gazer.  Extremely useful, but it only lasts 1 round.
  The OD&D spell only mentioned reflecting the gazes of basilisks and medusae.  It was given a range of 8", whereas in AD&D it's presumably effective at whatever range the creature's gaze has.  It lasted 1 turn, which might mean the same thing as the 1 round duration in AD&D.

Hypnotism: With gestures and a droning incantation, the caster can hypnotise 1-6 creatures and give them a suggestion (like the spell) that they will follow for the spell's duration (1 round + 1/level).  Suggestion as a spell in its own right only affects a single creature, so hypnotism is stronger in that regard, but it has a far shorter duration (minutes as opposed to hours).
  The OD&D spell worked like charm person, with a penalty opposed to the target's saving throw and the requirement that they look into the caster's eyes.  A completely different spell, basically.

Light: Works like the 1st-level m-u/cleric spell, creating a globe of light that illuminates a 2" radius.  It has the same specs as the m-u spell exactly.  It has half the range of the cleric spell (6" vs. 12"), a duration that's shorter by an hour, but a quicker casting time (1 segment vs. 4).
  The OD&D spell created a 3" diameter illumination, rather than the 4" of AD&D.

Phantasmal Force: Like the 3rd-level m-u spell, it creates a silent illusory creature or object that can damage foes who believe it is real.  It has a shorter range than the m-u version (6" + 1"/lvl vs. 8" + 1"/lvl), and a smaller area of effect (4" square + 1"/lvl vs. 8" square + 1"/lvl), but a quicker casting time (1 segment vs. 3).
  The OD&D spell, called phantasmal forces, mentioned nothing about the illusion having no sound.  It had a range of 24", far longer than most AD&D casters will ever manage.

Wall of Fog: Creates a fog in a 2"/level cubic area that obscures sight.  It can be dispersed by a strong breeze.  Its material component is a pinch of split dried peas.
  The OD&D spell mentioned nothing about strong breezes.  It had the dimensions of a wall of fire, which meant a flat wall 6" wide and 2" high, or a 3" diameter cylinder 2" high.  Its range was 16", far higher than AD&D's 3". No duration was given.