The Cavern of Sorrow
Call of Cthulhu
Call of Cthulhu mostly uses 10-sided dice in pairs as percentile dice (d100s). Every skill is represented as a pure percentage chance to hit (representing a target number), with situational modifiers at the Keeper’s discretion. 100 is always a failed roll, whereas with a roll of 01 a myopic man in a wheelchair could successfully parachute out of a burning plane. No battle mats are used (or not often).
If you haven’t played or heard of it, Call of Cthulhu is more suspense horror (“closed door”) – the PCs are ordinary people investigating mysterious circumstances. When horror appears, it blasts away sanity, and combat is brutally lethal. The vile, eldritch monsters that infest Cthulhu are so powerful and terrifying, the main object of the game is often to keep “the door” firmly SHUT, and the protect the world by keeping the monsters OUT. A good movie along this line is In the Mouth of Madness.
If you have played or heard of it, my disclaimer is this: I like this game because I like these stories. Cthulhu has a reputation as a game that allows the Keeper to kick his players’ collective ass. My philosophy is that I want to run an exciting story; I work extra hard at game balance in Cthulhu and pull no dirty tricks. I also don’t like the old “I read one book and it cost me all my sanity,” so I’ve got house rules for things like that.