Delving Deeper Illusionist.

Anybody try the Delving Deeper version of the Illusionist? It uses tricks to simulate spells, and I'm wondering how you would build that as per the PC, since the Illusionist "spells" don't map to the Arcane or Divine value. Because who doesn't want to play The Amazing Randi?

Seems simple enough to me; it’s a warlock build, Arcane 3 Thievery 1. The actual spells per day won’t match, but you just give them their own spell list (there’s no reason that an arcane class needs to have access to the wizard spell list, after all), and use the points in thievery to give them whatever custom powers cover the differences (such as immunity to detect or dispel magic).

(Of course, the fact that I describe it as simple doesn’t make it necessarily easy, because this would after all involve creating a great many new spells.)

That's a little bit trickier than you say, but it may be that the difference is minor enough that it doesn't make a big difference.

Basically, a portion of the XP cost of Arcane Value is that you get to research spells, so paying full XP and having your own list that you can't exit from is a bit of a nerf for this hypothetical new character.

My initial recommendation would be to use divine value instead and trade away turn undead for more special powers, since divine value is built with having a set spell list in mind, possibly modified by a proficiency, and then making a spell list of arcane spells.  This doesn't work perfectly either, however, because part of the costing of Divine Value is based on the fact that divine spells are just plain weaker than arcane spells for directly offensive purposes, offensive here including tricking your opponents.

It's a tough nut to crack, I'd say.  Time for Alex to release those rules he aluded to many posts ago about inveting custom magic systems.

I've made an Illusionist custom class for my campaign. Modeled on the Warlock, it swaps Arcane Spellcasting for at-will spell-like powers.
Here's the original blog post:
And here's the revised class description:
(Note that some of the spells are from ACKS Dwimmermount.)

I like your class write-ups for the specialty mages. My one issue with the class creation rules and making specialists this way is your illusions (or fire spells or ice spells etc) will be cast at 2/3 caster level - so they're actually worse than a regular mage at their specialty. I believe when I was creating something like this I limited their spell list (like a cleric) to keep them in a theme but gave them full caster level in their narrow speciality - so a pyromancer's fire spells are calculated at full level rather than 2/3 level, non-fire spells on their list are cast at 2/3 level, and mage spells off their list they simply can't cast at all.

True, but this is offset somewhat by the lower XP requirement.

In my current campaign, there is a Pyromancer PC who seemed a bit peeved when he reached 3rd level to not gain new spells. However, I pointed out that as a Mage he would still only be 2nd level at that point.

I think these specialist classes will be slightly more powerful than a mage at first, but will be less powerful by about 5th lvl. In return I've provided some other minor perks - Pyromancers and Cryomancers each get a 1d6 damage weapon, for example, and all specialists add signature spells to their repertoire for free.

I like the way you've built them and they're flavorful and I'm sure play just fine.

To me, the 2/3 progression specialist doesn't make sense unless somehow their specialty is better than a standard mage, at the cost of ability in all other areas outside their specialty. As they progress right now they're almost equal with their specialst spells (with the corresponding elementalist or illusion proficiency that they autromatically get) at comparable experience point levels (not quite), and in return they get a few additional abilities. However, a mage who invests in the proper proficiency will outdo the specialist at all levels after they hit 2nd or so. Even with the slightly more rapid level progression, I just can't wrap my head around a conqueror or king-level fire, ice, or illusion specialist not being any better at a fire, ice, or illusion spells than a mage, and with fewer spells overall per day to boot. Sure, they can throw a weaker version of their specialty more often than a regular mage, but the regular mage has more slots and a wider range of spells to throw into those slots at full caster level. I think that's why I went with the narrower list with barred spells but with their specialty at full caster level (and then add in the elementalist proficiency).

It really is a matter of taste - as I said I think your version is flavorful... I wouldn't grumble to play it. :-)

I agree “specialist” can be a matter of taste.

The Warlock “chassis” is the swift path to power, and/or the path to inherent ability.

Mage may be best compared to another Mage:

In my experience, limiting spell selection has a definite impact on play. Just “A specialist mage’s master will always teach the specialist a spell of the specialist’s selected spell type when a new spell level is gained” limits the player’s toolbox, along the lines of “every problem is a nail when you only have a hammer.”

As a player I like flexibility and would choose my Archivist or Generalist over Specialist or Focused.

Compare to the Witch, who has both slots and repertoire. Low to mid-levels, the Witch is very strong, limited only by her “themed” divine spell list.

Stepping away from class mechanics, Illusion spells are a difficult design space, especially with “specialization”. This is because being “limited” to an illusion which can be whatever the players wants at casting (to some extent) is not much of a limitation.

indeed one of the strengh of the AD&D 1st ed Illusionist was his peculiar spell list. An illusionist (or other specialist) should have special spell and a special list....