Why change the way spell casting works?
Because Vancian Magic sucks.
Clearly that’s just my opinion, but I know it’s shared by more than a few. Ever since the beginning of the hobby, players have been replacing the “memorize, fire, forget” system with different systems, most involving spell points of some sort.
This is not a spell point system. I think those add another level of book-keeping that I’d rather avoid.
I guess I should say why I don’t like Vancian magic. I’ve never read Jack Vance’s work, so his magic system doesn’t match my (pre-D&D) mental image of a magic user. If you were to ask young me to think of a magic user, there are four names that would have sprang to mind:
I can’t think of a single scene with any of these “classic” magicians that fits the “memorize, fire, forget” paradigm. Instead they have powers that they can do, and when they need to do them, they do them…
…And sometimes it doesn’t work.
…And sometimes it goes horribly wrong.
…And sometimes they temporarily lose their powers.
That’s what I want to recreate.
While I’m at it, I want to align spell levels with character levels.