Tic-Tac-Toe is one of the simplest and most widely recognized games in the world. Two players, a small grid, and a handful of turns are all it takes. This guide walks through every rule a beginner needs to know.

The Board

Tic-Tac-Toe is played on a 3×3 grid — nine empty squares arranged in three rows and three columns. You can draw it on paper, scratch it into sand, or play on a screen. The board starts completely empty.

Each square can hold exactly one mark for the entire game. Once a mark is placed, it cannot be moved or removed.

X and O

The two players each claim a symbol. One plays as X and the other plays as O. By long-standing convention, X takes the first turn. In casual play, players often swap symbols between rounds so that each person gets to go first equally often.

Taking Turns

Players alternate turns, one move per turn. On your turn you place your mark — X or O — in any empty square. You may not skip a turn, and you may not place your mark on a square that is already occupied.

Because there are nine squares and two players alternate, X will make five moves and O will make four moves if the game goes the full distance.

How to Win — Three in a Row

The goal is to place three of your marks in a straight line. That line can run in any of these directions:

  • Horizontally — across any of the three rows
  • Vertically — down any of the three columns
  • Diagonally — from one corner through the center to the opposite corner

There are exactly eight possible winning lines on a standard board: three rows, three columns, and two diagonals. The first player to complete any one of those lines wins immediately.

Draws — The Cat’s Game

If every square is filled and neither player has completed a line of three, the game ends in a draw. This outcome is colloquially known as a “cat’s game” in North America. Draws are extremely common between experienced players — in fact, with perfect play from both sides, a draw is the guaranteed result every time.

Quick-Start Summary

  1. Draw or open a 3×3 grid.
  2. Decide who plays X (that player goes first).
  3. Take turns placing your mark in an empty square.
  4. The first player to get three marks in a horizontal, vertical, or diagonal line wins.
  5. If all nine squares are filled with no winner, the game is a draw.

Common Beginner Mistakes

Ignoring the center. The center square touches all eight winning lines (four of them pass through it). Leaving it open for your opponent is risky.

Focusing only on your own line. New players often concentrate on building their own three-in-a-row and forget to block the opponent. Always scan the board for threats before making an offensive move.

Playing randomly in corners vs. edges. Corner squares participate in three winning lines each, while edge squares participate in only two. Corners are generally more valuable positions.

Where to Go Next

Once you are comfortable with the rules, learn how to apply basic strategy so you never lose a game. You can also explore the glossary to get familiar with common terms players use when discussing Tic-Tac-Toe positions and tactics.