The game is played until a terminal position is reached.
Furthermore, impartial games are played with perfect information and no chance moves, meaning all information about the game and operations for both players are visible to both players.
Impartial games include Nim, Sprouts, Kayles, Quarto, Cram, Chomp, Subtract a square, Notakto, and poset games.
Go and chess are not impartial, as each player can only place or move pieces of their own color.
Impartial games can be analyzed using the Sprague–Grundy theorem, stating that every impartial game under the normal play convention is equivalent to a nimber.