A zero-player game or no-player game is a simulation game that has no sentient players.^[1]

There are various different types of games that can be considered "zero-player".^[2]

A game that evolves as determined by its initial state, requiring no further input from humans is considered a zero-player game.^[3]

Cellular automaton games that are determined by initial conditions including Conway's Game of Life are examples of this.^[4][5]

Progress Quest is another example, in the game the player sets up an artificial character, and afterwards the game plays itself with no further input from the player.^[6] Godville is a similar game that took inspiration from Progress Quest.^[7] In the game, the player is a god that can communicate with a non-player character hero.^[8] However, the game can progress with no interaction from the player.^[9]

Incremental games, sometimes called idle games or clicker games, are games which do require some player intervention near the beginning however may be zero-player at higher levels.^[10] As an example, Cookie Clicker requires that players click cookies manually before purchasing assets to click cookies in the place of the player independently.^[11]

In computer games, the term refers to programs that use artificial intelligence rather than human players,^[12] for example some fighting and real-time strategy games can be put into zero-player mode where multiple AIs can play against each other. Humans may have a challenge in designing the AI and giving it sufficient skill to play the game well, but the actual evolution of the game has no human intervention.^[13]

• Single-player game
• Two-player game
• Multiplayer video game
• Incremental game