Numerical Tic Tac Toe vs Tic Tac Toe ² (Ultimate)

Numerical tic-tac-toe is a variant of tic-tac-toe that replaces the traditional Xs and Os with odd and even numbers. Players alternate placing numbers, aiming to form a line that adds up to 15.  The game is played on a normal nine square tic-tac-toe board. The odd player begins with the numbers 1, 3, 5, 7, and 9. The even player begins with the numbers 2, 4, 6, and 8. Odd always goes first. The two sides alternate placing numbers on the board in empty squares. Numbers cannot be repeated. So, there will only ever be a single instance of each number on the board. The first player to put a number down that achieves a sum of 15 composed of three numbers in a row, column, or diagonal wins the game. Note, that two numbers adding to 15 is not sufficient. So, a 6 next to a 9 is not a win. *Features* - Play against an AI opponent - Play against a friend - Three levels of difficulty - Customizable colors *History* Numerical tic-tac-toe was invented in the late 1950s by American mathematician Ronald Graham. A similar game was contemporaneously invented by P.H. Nygaard. In 1990, George Markowsy wrote a computer program that solved numerical tic-tac-toe. He proved that 1 in the top middle slot is a winning first move for odd. In other words, in perfect play, odd wins the game. Markowsky published his findings in The Journal of Recreational Mathematics.

Game Setup: • Board Structure: The game features a large 3x3 grid, with each cell containing a smaller 3x3 grid (making a total of 9 smaller grids). • Players: Two players take turns, represented as ■ and ●. Basic Gameplay: 1. First Move: ▪ The first player can place their mark (■) anywhere in any of the 81 empty cells across the entire board. 2. Subsequent Moves: ▪ The location of a player’s move determines which smaller 3x3 grid their opponent must play in next. ▪ For example, if Player 1 plays in the top-right cell of a small grid, Player 2 must then play their next move in the top-right small grid of the large board. ▪ If a move sends the opponent to a small grid that is already won or full, the opponent may choose any of the remaining cells on the entire board.