User summary
Polaris is a diceless and GM-less role-playing system relying on "keyphrases" by which the players negotiate what they want to happen, and what prize they are willing pay (that is, what sacrifice they are willing to make in the story).
The Polaris system was created in 2004 by Ben Lehman for his entry in the Game Chef competition, an indie RPG design contest. His game Polaris: Chivalric Tragedy at Utmost North won great acclaim.
Later, Anna Kreider used the system for her game Thou Art But A Warrior (first published as an alternate setting to Ben Lehman's game, before it was published as a standalone RPG).