Chess is a game of strategy and tactics played on a board with 64 squares. The game is played by two players, who move their pieces around the board according to a set of rules. The object of the game is to capture the opponent's pieces, or to block the opponent's pieces from moving.
A complex chess strategy is a chess opening in which the player sacrifices material, usually a pawn, with the hope of achieving an advantageous position.
The most common complex chess opening is the French Defense, in which Black sacrifices a pawn to gain control of the center of the board. Other common complex chess openings include the King's Indian Defense, the Nimzo-Indian Defense, and the Caro-Kann Defense.