[panton41]

It's an obscure books and the magic system is best converted to Fate Core, but Deliria is pretty much laser focused for Charles de Lint style urban fantasy.

I point you to Wikipedia because it's been out of print for years and the original author regrets how he wrote the rules. Broadly speaking he wrote the game in really poetic purple prose... even the gameplay rules.. which he realized years later that people liked rules written like stereo instructions.

The rules are almost impossible to translate into GURPS (and trivial for Fate Core, but so is the difference between the systems). But basically if two stats reached a certain level it was a simple dice roll for anyone at all to do magic. In Fate that's a High Concept and Skill (maybe Stunt), but in GURPS it's more complex. Basically, like if someone had to roll against (IQ+DX)/2=Magic (or (IQ+HT)/2) where IQ and DX/HT had to be 12+ and no other modifiers were allowed, but beyond that any ability was allowed.