Hollywood Squares is a long-running American TV game show in which celebrities sit in the 9 squares of a vertically-arranged tic-tac-toe board. The celebrities, who are given both the questions and the correct answers before the show, are asked trivia questions by the host. The contestants must either agree or disagree with the celebrity answer.
If the contestant agrees or disagrees correctly, their symbol (X or O) is placed in the square; otherwise, their opponent's symbol is placed there. To win the game, however, a player cannot take advantage of their opponent's mistake; they must respond correctly on their own turn.
Since the center square tends to get picked most often, generally the most famous or amusing celebrity is placed there. The late Paul Lynde was the center square for the program's original run between 1968 and 1981; other center squares of later versions have included Joan Rivers, Whoopi Goldberg and Ellen DeGeneres.