3-D Tic-Tac-Toe is a video game released by Atari, Inc for the Atari 2600 console and Atari 8-bit computers in 1980.
The game is similar to the traditional game of tic-tac-toe, but is played on four 4 x 4 grids stacked vertically on top of each other; it is basically a computerized version of the board game Qubic using traditional tic-tac-toe notation and layout. To win, a player must place four of their symbols on four squares that line up vertically, horizontally, or diagonally, on a single grid, or spaced evenly over all four grids. This creates a total of 76 possible ways to win, in comparison to eight possible ways to win on a standard 3 x 3 board.
The game has nine variations, it can be played by two players against each other, or one player can play against a built-in AI on one of eight different difficulty settings. The game uses the standard joystick controller.
3-D Tic-Tac-Toe was written by Carol Shaw, who went on to greater fame as the creator of Activision's River Raid.
The game was remade for the Microsoft Entertainment Pack as TicTactics; this version also allowed the game to be played inside a 3 x 3 x 3 grid.