Boter, kaas en eieren (Butter, cheese, and eggs) is the Dutch name for Tic-tac-toe. The game is played by two players who take turns in filling in squares in a 3 by 3 matrix. One player puts in X's and the other player puts in O's. The first player who has three of X's or O's in a row wins. The rows can be horizontal, vertical and diagonal.