A Cyber Oculus web page (Copyright 1998-2000) describes Tic-Tac-Toe as follows:
The object of Tic Tac Toe is to get three in a row. You play on a three by three game board. The first player is known as X and the second is O. Players alternate placing Xs and Os on the game board until either oppent has three in a row or all nine squares are filled. X always goes first, and in the event that no one has three in a row, the stalemate is called a cat game.