Torres Quevedo's El Ajedrecista was the first true game-playing machine

Around 1912 the Spanish engineer Leonardo Torres Quevedo built El Ajedrecista, “the chess player.” Unlike the eighteenth-century Mechanical Turk, which hid a human operator, it was a genuine automaton: electrical sensors under the board detected where the opponent had moved a lone king, built-in rules chose the reply, and the machine moved its own rook and king to drive the opposing king to checkmate, regardless of the starting position. By common account it was the first machine that could play a game and make its own decisions about how to win, rather than merely calculate or display a fixed result.