While the game of tic-tac-toe is really old, dating back to ancient Egyptians at around 1300 B.C., the underlying principles of the game have endured the test of time. The game seems simple enough. Two opponents, one using X and one using O, use a 3 x 3 grid to mark their symbols. The first one to get all three of his/her symbols in a row, whether it’s diagonal, horizontal, or vertical, wins the play tic tac toe game. The ingenious catch here for children, which adults find trivial, is that the game is designed to end up in a draw. Only when one opponent makes a mistake will the other opponent win. This is where the simple game of tic-tac-toe gets a little more complicated: https://playtictactoe.io