In The Last Spell you command a group of heroes in turn-based combat as they try to protect mages casting the titular spell that is to push back the mist enveloping the world and spawning hordes of monsters. This spell is going to take days to finish and every night waves of enemies come to attack the city, with your heroes and whatever ruins remain and defenses you build as the only means to slow the assault. Failure comes from all of your heroes dying or the mages being killed, and if that happens, you can try again with another set of procedurally generated heroes against the procedurally generated enemies.