I'm still – slowly – working on the ideas I've got from the last section, but it's high time I resumed this series.
Recovery of Spells
Gary gives a short table for how long you have to sleep to be able to memorize new spells; these range from just four hours, if all you want to memorize are first or second level spells, all the way to a whopping twelve hours if you want to memorize a ninth level spell. The implications for this are interesting: low level Magic-Users, Clerics and other spell casters now have no excuse for not standing watch at night, and there may come times when a high-level character chooses not to rest long enough to memorize their highest level spells. Interrupting a high-level enemy Magic-User's 12 hours sleep certainly becomes an attractive strategy. While I find all of these ideas interesting, though, I just don't expect them to come up that often in gaming, or perhaps to even come up at all.
After a spell caster has rested sufficiently, each spell takes 15 minutes per spell level to memorize. Even more than resting times, I've always had a problem with this approach, for a few reasons. Again, I don't really see the point of the extra math, it doesn't fit my reading of the source material in the Tales of the Dying Earth (specifically in the first few pages of Turjan of Miir), and, least logically but most viscerally, it clashes with my preferred metaphor for Vancian magic: loading bullets into a gun, which is quick and easy.
Insight into how variable rest time and lengthy spell memorization times make the game better is very much appreciated.
Gary goes into a half page of explanation of how AD&D Vancian magic works, in-game. Basically, each spell brings energy from another plane to the caster's plane and channels it into the spell's effects. In exchange for the energy from the other plane, material components (the caster's breath, when none are listed) are destroyed to provide the energy to send back to the other plane.
Gary also mentions the the first two Dying Earth books (The Eyes of the Overworld and The Dying Earth) and John Bellairs' The Face in the Frost, a book I haven't heard of before or remember reading any reviews of on OSR blogs, as inspiration for the way AD&D magic works. I'm guessing that a good deal of the elements of AD&D magic I don't recognize from Vance are from the latter work, which seems to be highly recommended by Bellairs' fellow fantasy writers. The Face in the Frost is now on my reading list.
On the other hand, even if I thought that Vancian magic needed this level of explanation, I don't like this explanation of how magic works. This isn't making it into my game.
Tribal Spell Casters
Certain humanoids and a few other groups (cavemen, ettins…) have spell casters in their tribes. Shamans are the tribal equivalent of Clerics and may go up to 7th level, depending on species, while Witch Doctors are the tribal equivalent of Magic-Users and may go up to 4th level, depending on species. Both NPC classes have limited spell lists and only Cavemen may have both a Shaman and Witch Doctor in one tribe. Altogether, a helpful but not terribly exciting section.