A replay is a storytelling method (roleplaying fiction) that has been in use in Japan for quite some time. Some examples of replay based stories are Record of Lodoss Wars, Rune Soldier and Red Dragon. A replay is more or less a transcript of an actual tabletop game, in which the main heroes are all played by actual people in a live game session. That transcript is then formatted and arranged in a way that is easier to read, but still maintains its “spectator feel”.
The interesting thing about replays is that they’re completely unpredictable! Random events occur, and a simple roll of the dice can take a controlled situation and turn it on its head. The characters work together for better or for worse to create a unique and natural experience that can only be achieved through the characters being players.