This probably has been thought up before but I've been considering easy ways to factor in casting spells while taking damage that don't require lots of fucking about with tables and such.
A roll against Int when you take damage while casting (Wis for a cleric I guess), plus your level, minus spell level, minus the damage taken. Pass and cast normally, fail and no spell.
Easy, no?
Plus you can add spell fumble tables if youve got the inclination, maybe stick some mutations in for extra fun?
