2 to 6 players. No GM.
Round 1: Arrange chairs, one for each player, in a circle. Face chairs away from center of the circle; sit down. Nobody should see anyone else.
Oldest player goes first. Assume a character. Tell a story relating an event in your PC's past; establish at least one other character in your story.
Play progresses clockwise. Each player must assume a character mentioned by a previous player (no repeats). Players must reveal why they no longer have contact with the previous character.
Round 2: Turn chairs around, facing center.
Play in reverse order, progressing counter-clockwise. Each player initiates a scene with another character. Scene may be past or present. Other players may join, but only as their own characters; no NPCs. No time limit on scenes.
Round 3: Turn chairs around, facing away away from center.
Random order. Initiate a phone call scene with another character. Scenes must end either positively or negatively for the initiating player – no neutral scenes.
Final Round: Face chairs inward.
Round 1 play order. Players each roll d12, then narrate an epilogue to their character's story using the exact number of words equal to d12+4.
End game.
I was inspired by freeform games like Fiasco and Out of Dodge. I also used an element or two that I learned when I worked improv comedy professionally, mechanics that are designed to cultivate creativity within some parameters.