X and O alone do not fully specify a game. Board size, winning length, placement and game ending matter. This overview distinguishes our three current sizes from related games and explains why outside advice cannot be transferred blindly.
In this guide
Our variants at a glance
X starts on local boards. In live rooms, the creator selects size and starting player before play. All three sizes alternate one mark on an empty cell. Personal display or sound options do not change the room rule.
| Board | Objective and placement |
|---|---|
| 3×3 | Three consecutive; free placement |
| 4×4 | Four consecutive; free placement |
| 5×5 | Four consecutive; free placement |
Gomoku and spatial forms are different games
MathWorld places tic-tac-toe within generalised line games. Gomoku uses a five-line objective, while qubic uses a spatial 4×4×4 board. These names are therefore not interchangeable labels for our 5×5 four-line rules. The familiar perfect-play draw on 3×3 does not automatically settle a different rule combination.
Further reading: Eric W. Weisstein: Tic-Tac-Toe, Wolfram MathWorld
Four in a row with or without gravity
Our Four in a Row has seven columns, six rows and falling discs. Select a column and fill its lowest empty cell. In tic-tac-toe, select the cell directly. A diagonal target can be unreachable in a gravity game even when the same geometric pattern would win immediately with free placement.
Before using an outside guide
Check the size, required consecutive length, whether longer lines count, free placement versus gravity, valid diagonals and when play stops. Our rules accept a four-cell winning segment within five own marks, and a win ends the played round immediately.
For our larger boards, use the dedicated 4×4 and 5×5 guide. It counts the windows actually checked here rather than importing rules from five-in-a-row or a three-dimensional board.