Overcasting (p. 214) #

Even if a character spends all of their spell uses, they can still use more spells. This is called Overcasting (also called limit-breaking, overusage, or overprayer).

When using a spell in an Overcasting state, the character suffers 2d6 points of fatigue immediately after performing a spell use check and applying the spell’s effects. For spells that require spell maintenance up until the point where they activate, the character suffers 2d6 points of fatigue either when that spell maintenance breaks or when they make their spell use check on the final round and apply the spell’s effects.