This is another one of those strange places where I used to see a great many House Rules – and certainly where I had ones myself. This could also segue into a discussion of spell points (which I never used, at worst I glued Call of Cthulhu or Rolemaster magical systems on top of AD&D), but unless you wanted a radically different flavor of magic then the Vancian system works fine.
The problem with low powered mages and no bonus spells for mages is handled in my post here
But in general, my thoughts on the greater question of spell memorization is as follows. Mages cast spells, clerics use prayers, and psychics use abilities. If we accept the Vancian system, we really shouldn’t be mucking with mages – but why the heck would priests forget their own prayers to their deity? So, that meant that Clerics merely had a pool of prayers that they had access and could use them as needed – up to the limit of “spells per day per level”. Psychics don’t forget their minor disciplines or their major sciences when using them, so if we viewed some forms of “magic” as being more akin to “psionics” then those people didn’t need to memorize spells either – though they might have to learn “spells” in a manner similar to a mage – and that is how I saw illusionists. I also saw Druids as being much more like mages when it came to how they used magic, so while they are still considered “priests” in all other respects, they memorize thier spells like magics because they’re super-nature focused and divinely inspired and guided mages.
I even had a half-dragon Fighter/Magic-User long before anything like a Sorcerer saw the print in a D&D supplement who pretty much did the same thing – right down to the draconic heritage. I really have to wonder at times if one of my old players is working for TSR/WOTC/Hasbro…
In any case, here is the breakdown of who has to memorize spells, who has priestly-style prayers, and who has psychic-style talents.
- Arcane Spells: Mages, Hedge Mages, Druids, Elementalists, Necromancer, Minstrels, and Rangers.
- Divine Prayers: Clerics, Templars, Shaman, Healers, and Champions.
- Mentalist Talents: Illusionists, Incantatrixes, Mountebanks, Oracles, and Timelords.
Alchemists don’t use spells, they have formula, and Psionicists gain Minor Devotions, Major Sciences, and Grand Arts as they go up in level. All of this gives the various “spell-casting” classes different flavors, strengths, and weaknesses. The biggest change is from my old AD&D campaign is that instead of nailing on new magic systems I’m just using various NPC classes and/or granting certain races major exceptions to some rules (ala elves not using material components).
There are handful of special cases; Diabolists treat their 1st through 3rd level spells as Divine Prayers while thier 4th through 7th level spells are treated as Arcane Magic. Bards treat their Songs of Power and their Illusionist magic as Arcane Magic if the issue comes up, but don’t have to memorize any of them beforehand. Similarly, Sorcerers and Tantrics are considered to be using Arcane Magic but do not have to memorize their spells in the same way that Mages do.