Warrior Poet is an RPG where the players resolve conflict by writing lines of haiku. From the author’s description:
A four-player tabletop roleplaying game set in the final days of the Empire of the Moon. Take on the role of a heartbreakingly beautiful Warrior-Poet and duel using the ancient art of battle-haiku to establish dominance; to protect the Empire from threats within and without; to love, and be loved..
Seriously.
It actually looks like it would be fun for an evening with the right group.