A spectating system that generates game inputs based on spectating inputs and provides the game inputs to game systems according to an application programming interface (API). The spectating inputs may include spectator participation statistics, text chat inputs, audio inputs, and spectator interactions with a spectating user interface. The game inputs may include random numbers based on the spectating inputs that may be used as entropy sources for games. The game inputs may also include parameter inputs that provide values for parameters in the game based on spectating inputs. The spectators may become involved in the games being broadcast by influencing game play via the spectating inputs. Game play for the players may be enhanced by providing interesting variations in game play based on the spectating inputs.