Dread is an ENnie-award-winning diceless horror RPG that uses a tower of blocks, such as Jenga, as its task resolution mechanics. For character creation, the GM presents each player with a questionnaire that guarantees each character will fit in the scenario, and the players answer each question, fleshing out important details about their characters.
Task resolution at its most basic is thus -- when you attempt to do something particularly risky or story-relevant, you can make a pull from the tower to succeed. Or you can refuse to pull and automatically fail the task. If your pull causes the tower to fall, your character is removed from the game -- dead, irreversibly insane, captured, imprisoned, etc. There are a number of optional rules, including "dead man walking" and "heroic death," which give some narrative control to the players.
Not to be confused with Dread: The First Book of Pandemonium.