How to Play O×O

O×O is a fast, three-in-a-row strategy game built around three ring sizes that stack. It is easy to learn in a minute, but the stacking and multiple win paths give it real depth. Here are the complete rules.

What you are playing with

The board is a 3×3 grid — nine cells. Each cell can hold up to three rings: a large (outer) ring, a medium ring, and a small (inner) ring. Every player has a full set of pieces in their color, containing three larges, three mediums, and three smalls. Because the rings nest, a single cell can contain one player's large ring on the outside, another player's medium in the middle, and a third player's small in the center — all at the same time.

Setup

Each player receives nine rings in their color: three small, three medium, and three large. The 3×3 board starts completely empty, and rings enter it one per turn — so every game builds up gradually from a blank grid to a crowded, layered board.

O×O board mid-game with nested colored rings — A game in progress — rings of different sizes share the grid, some nested in the same cell.

Number of players

2 players

In a head-to-head match each player runs two colors and plays rings from both sets. Either color can deliver the win, but a winning pattern must be built entirely from one color — you cannot mix your two colors in a single line. Player 1 opens the game and turns alternate from there, one ring per turn.

Two-player colour assignment in O×O — In the two-player game each side controls two colours.

3–4 players

With three or four players, everyone commands a single color. Turns pass around the table in order, one ring per turn. More players means more colors fighting for the same nine cells, so blocking becomes just as important as building.

Taking a turn

On your turn you place exactly one of your pieces into the center grid. You may put it in any empty cell, or nest it inside a cell where that size is still free — for example, dropping your small ring into the middle of a cell that already holds someone else's large ring. A few firm rules govern placement:

Placed rings are permanent — there is no moving or taking back.
If none of your remaining rings fit anywhere on the board, your turn is skipped.
The round ends the moment a player completes any winning pattern.

The three ways to win

Victory goes to the first player who completes one of three patterns, and each of them counts across any row, column, or diagonal.

1. Three of the same size in a line

Place three rings of the same size — all large, all medium, or all small — of your color in a straight line across a row, a column, or a diagonal.

Winning with three same-size rings in a row — Three same-size rings of one colour in a line.

2. A full stack in a single cell

Place all three of your own sizes — large, medium, and small — stacked together inside one single cell. Completing your own nested stack in any one square wins immediately.

Winning by stacking all three sizes in one cell — All three of your sizes nested in one cell.

3. An ascending or descending diagonal

Line up your rings in increasing or decreasing size along a line — small, then medium, then large (or large, medium, small). This graduated line is the subtlest win and the one opponents most often miss.

Winning with an ascending or descending size line — Rings ordered by size — small, medium, large.

Tip: Every ring you place is also a block. Nesting one of your rings inside an opponent's cell can shut down their stack — watch their patterns as closely as your own.

Ready to play?

You can play O×O free in your browser — locally against friends on one device, or online in ranked matches against players worldwide.

Play O×O now