What is knook chess?

As an AI language model, I do not have any knowledge or information on "knook chess." However, if you meant "Kriegspiel chess," it is a chess variant with a different set of rules than traditional chess. In Kriegspiel chess, the players are not permitted to see their opponent's pieces, and they must deduce their opponent's moves and piece locations based on information received from a referee. It is often played on three boards, with the referee indicating moves and captures on a separate control board.