Kriegspiel is a chess variant invented by Henry Michael Temple in 1899 and based upon the original Kriegsspiel (German for war game) developed by Georg von Reiswitz in 1812.

For this reason, it is necessary to have a third person (or computer) act as an umpire, with full information about the progress of the game.

Since the position of the opponent's pieces is unknown, Kriegspiel is a game of imperfect information.

On the Internet Chess Club, Kriegspiel is called Wild 16.

The game is played with three boards, one for each player; the third is for the umpire (and spectators).

when a player has no pawns left is treated as an illegal move and answered "Hell no" (or "Impossible", "Nonsense").

(In a real Kriegspiel game, Black would not see White's moves, but for a problem in which White is to force a win, one must assume the worst-case scenario in which Black guesses correctly on each move.)

Additionally, White should avoid placing his pieces on the a7–g1 diagonal prematurely because the invisible black bishop could be guarding that diagonal and capture the white pieces upon entering it, leading to a draw.