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.