Astral Spell: This works much like the 7th-level cleric spell, in that it allows the caster and up to five others to travel through the Astral Plane, and into the Outer Planes. The only difference is that a magic-user can cast it in 9 segments, whereas it takes a cleric 3 turns.
See the link above for my comparison between the OD&D and AD&D versions of the spell. One thing I didn't mention is that in OD&D if the caster's physical body was moved so that the spirit became out of range, they were sent to "jibber and shriek on the floor of the lowest hell". The spell also had a much higher range when used outside than it did underground. Really, the OD&D and AD&D versions of this spell have completely different uses. In AD&D it's a spell for planar travel, but in OD&D it seems more useful for exploration, reconnaissance and perhaps some spell-casting on unsuspecting enemies.
Bigby's Crushing Hand: The final spell in the Bigby's hand series creates a giant hand that squeezes a single opponent. It deals 1d10 damage on the first round, 2-20 damage on the 2nd and 3rd rounds, and 4-40 damage on every round thereafter. It lasts for 1 round per caster level, so that's a lot of potential damage. The hand only has as many hit points as the caster, though, which probably won't be a lot even for a high-level magic-user. It's material components are a snakeskin glove and an eggshell.
Gate: Like the 7th-level cleric spell, this creates a portal to another plane and summons a powerful being that may or may not grant the caster some aid depending on the circumstances. The only difference between the cleric and magic-user spells is that clerics have a casting time of 5 segments, and magic-users take 9 segments. It's a rare case of the cleric spell being quicker to cast than the magic-user's.
The link above (under Astral Spell) also details the difference between OD&D and AD&D. Mostly it was that OD&D gave more specific examples of the type of creature that could be summoned (Crom, Set, Cthulhu, etc.).
Imprisonment: Any victim touched by the caster of this spell will be entombed far beneath the earth, in perfect suspended animation. Nothing can free the victim except for the reverse of this spell, freedom, and even then the caster needs the victim's the name and background. If this information isn't exact, there's a 10% chance that 1-100 other imprisoned creatures are also set free. (One thing I love about Gygaxian D&D are the little touches that are there to screw over PCs who haven't done the adequate preparation. High-level spells are powerful, but just about all of them have a catch.)
Meteor Swarm: I had a little trouble figuring out exactly how this spell works, but here's what I got. The spell creates either four 2' orbs, or eight 1' orbs, that streak to the distance chosen by the caster. Any creature in that path is affected as though hit by a fireball. The orbs explode in a pattern at their destination, with the larger orbs dealing 10-40 damage and the smaller ones dealing 5-20. These explosions can overlap, so certain targets will be hit twice, or possibly four times if they are at the direct centre. This is a spell that could really benefit from a diagram, particularly for the eight-orb version..
The OD&D version of the spell simply creates four fireballs that can be thrown as the caster desires, or eight fireballs of half strength. It's a much simpler spell, and still quite potent. I'm not sure why Gary felt the need to overcomplicate it.
Monster Summoning VII: Summons 1-2 7th-level monsters, or a single 8th-level monster. If we go to the OD&D spell, it recommends that the DM use their own special tables, but gives some example monsters: iron golems, a 20th-level lich, a ten-headed fire-breathing hydra, and others. As for 8th-level monsters, those aren't catered for by the OD&D rules. For this spell, I'm going to jump ahead to the at-this-time unreleased Dungeon Master's Guide, and see what this spell can really do. For 7th-level monsters, it's a lot of demon and devils, and a bunch of other very strong monsters (including a 10-12 headed hydra). For 8th-level, it's much the same, but has Type VI demons and purple worms, and just a load of very, very nasty creatures. Neither of them feature a 20th-level Lich, so I feel like OD&D is still a more powerful spell on the whole.
Power Word, Kill: This spell will kill a single creature of up to 60 hit points, or a bunch of creatures with less than 10 hp (totalling 120 hp worth). It has no saving throw, so it's good for knocking off one strong foe or a bunch of small ones. Probably not going to work on any boss monsters, though. (That said, my sense of AD&D's power scale is off because I haven't played it in so long - it might be that a lot of powerful monsters won't have more than 60 hp. I remember the spider queen Lolth only having 66 hp in Vault of the Drow, for example.)
The OD&D spell killed a single creature with up to 50 hp, so it's notably less versatile. (It might be about as effective otherwise, due to OD&D monsters rolling their hp on 1d6, as opposed to 1d8 in AD&D).
Prismatic Sphere: The caster is surrounded by a number of shimmering globes, each of a different colour and effect as follows:
- Red - prevents all normal missiles; inflicts 10 damage on those passing through; destroyed by cone of cold
- Orange - prevents magical missiles; inflicts 20 damage on those passing through; destroyed by gust of wind
- Yellow - prevents poison, gas, and petrification; inflicts 40 damage on those passing through; destroyed by disintegrate
- Green - prevents all breath weapons; death to those passing through; destroyed by passwall
- Blue - prevents detection and psionics; petrification to those passing through; destroyed by magic missile
- Indigo - prevents all spells; insanity to those passing through; destroyed by continual light
- Violet - force field; sends those passing through to another plane; destroyed by dispel magic
The OD&D spell was actually called prismatic wall, but it still created a globe. It was the same spell in general, but the specifics were quite different, with the effects and weaknesses of the different colours being mixed around. Red and orange, for example, have their effects swapped, and the red globe is vulnerable to ice storm rather than cone of cold. The blue globe protects against cleric spells, and there's no globe that prevents poison, gas or petrification. There's also no globe that sends the victim to another plane; it replaced one that freezes the victim to death. No colour is exactly the same between editions.
Shape Change: For the duration of the spell (a hefty 1 turn/level) the caster can assume the shape of pretty much any being, gaining all of its physical attributes (although retaining the caster's own hit points). The only restriction given is that the caster can't become a demi-god, greater devil, demon prince, greater demon, or a singular dragon (like Tiamat). The caster can change shape as often as they want while the spell lasts, and doesn't incur a system shock roll. Although at the start it says the caster can become a creature, some example forms given later are a bush and a pool of water, so I guess it extends to objects as well. The material component is a jade circlet worth 5,000 gp. This circlet is left behind during the first transformation, and if it is shattered the spell ends.
The OD&D spell was much similar, though it had no stated restriction on the power of the creature that could be mimicked. It didn't specifically state that mental abilities weren't gained, but a reference back to polymorph other implies it pretty strongly, I feel.
Temporal Stasis: This spell places a single target in suspended animation, permanently and with no saving throw. It can be removed with dispel magic or the reverse of this spell (temporal reinstatement). The material component is a powder made of diamond, ruby, emerald, and sapphire, although the reversed spell doesn't require it. The biggest oversight of this spell, I feel, is that it doesn't say anything about what happens when the creature in stasis is attacked. I'd be inclined to make them impervious to harm, because any creature hit by this spell is pretty much out of the game anyway.
Time Stop: The caster stops the flow of time within a 3" diameter sphere. Anyone who enters will be frozen in time, except for the caster, who can move and act freely. This is another spell that can use some clarification on whether murders can be done to frozen individuals. For this spell, I would rule yes, because only the caster can act, and the duration is measured in segments - there's only so much one character can do.
The OD&D spell affected a cube rather than a sphere, and had a longer duration of 2-5 rounds.
Wish: This spell can pretty much do anything, but is dependent on the exact wording used, and the DM is encouraged to punish players using it for unfair purposes. (The example given is a character wishing another character dead, and thus being transported to a time in the future when that character is no longer living, thus putting the wisher out of the game.) It has no negative effect on the caster if it's used for healing, resurrection or to escape from a bad situation, but for everything else it drains 3 points of Strength and requires 2-8 days of bed rest.
The OD&D spell was the same, but it didn't require bed rest after casting; instead, the caster was unable to cast spells for 2-8 days.
And, that is finally it for magic-user spells. I still have the illusionist list to go, but that has less spells per level to deal with, and less levels overall. I can see the light at the end of this self-made tunnel. I got caught in a similar trap of providing too much detail with the Monster Manual as well, but after this it should be a good long while before I encounter a similar situation. The variety will be much appreciated by me, that's for sure.