During last gaming session this situation happened:
the fighter was held prisoner and the sorcerer cast on him invisibility but after a round or two the fighter was unable to escape (they were fighting on fresh snow) and had to end his spell (without attacking anyone) in order to save his life.
In my opinion he could have done it at will; but the sorc. said he was the only who could end the spell if the fighter didn't anything that make invisibility end (such as attacks).
How would you rule this?
the fighter was held prisoner and the sorcerer cast on him invisibility but after a round or two the fighter was unable to escape (they were fighting on fresh snow) and had to end his spell (without attacking anyone) in order to save his life.
In my opinion he could have done it at will; but the sorc. said he was the only who could end the spell if the fighter didn't anything that make invisibility end (such as attacks).
How would you rule this?