1. The game starts with an empty 3x3 grid. 2. One player is assigned the symbol X and the other O. 3. Players take turns to place their symbols in an empty cell of the grid. 4. The first player to get three of their symbols in a row (horizontally, vertically, or diagonally) wins the game. 5. If all the cells are filled and no player has three in a row, the game is a draw.