Ed Reppert wrote:
I've never really liked the "spell slots" approach. It seems too contrived*. The most elegant system, to me, is something like Harnmaster's: every spell is a skill, your mastery of that skill (a number between roughly 0 and something a bit over 100) defines how good you are at casting the spell; casting a spell makes you tired; when you get too tired, your spells start to misfire; misfire is bad.
* this is especially true with the two classes in this book, where you only have slots in your two highest spell levels, any you used to have in lower levels disappear when you gain levels. That's almost as bad as "once you cast a spell you forget how to cast it until you get a good night's sleep", which is just plain silly IMO.
Really, anyone who thinks spell slots are too contrived really should just go read (hopefully re-read) "The Dying Earth" by Jack Vance. This magic system has specific literary roots (some classic D&D spell names like 'Prismatic Spray' are lifted directly from that book) and makes perfect sense within that literary context.
Vancian magic is awesome, reflecting one of the most well-developed and thoroughly documented magic systems found in early (pre-video-game) fantasy literature and is core to the roots of Pathfinder (and all D&D versions or D&D clones).
(tiny excerpt) "Mazirian stroked his chin... Later, when black night lay across the forest, he would seek through his books for spells to guard him through the unpredictable glades. They would be poignant corrosive spells, of such a nature that one would daunt the brain of an ordinary man. Mazirian, by dint of stringent exercise, could encompass four of the most formidable, or six of the lesser spells."