Caro

How to play

Two games, one idea: line up your marks before your opponent does. Here is everything you need to know.

3 × 3 tic-tac-toe

  • The board has nine squares. X moves first, then players alternate.
  • Three of your marks in a row, column or diagonal wins.
  • If all nine squares fill up with no line, the game is a draw. With perfect play it is always a draw, so the fun is catching a mistake.

Caro (five in a row)

  • Caro, known internationally as gomoku, is played on a grid with no edges. Pan and zoom the board as far as you like.
  • X moves first. Players alternate placing one mark on any empty square.
  • Five or more of your marks in an unbroken row, column or diagonal wins.
  • Because the board never ends, there is no draw by running out of space; games are decided by threats such as open threes and fours.

Tips for caro

  • An open three (three in a row with both ends free) must be answered, or it becomes an unstoppable open four.
  • Look for forks: a move that creates two threats at once usually wins.
  • Block early. It is cheaper to stop a two than a four.

Clocks, resigning and rematches

  • Each turn has a clock: 20 seconds in 3 × 3 and 30 seconds in caro. If it runs out, you forfeit the game. A player who disconnects or closes the app has 30 seconds to come back, otherwise the player who stayed wins.
  • You can resign at any time. After a game either player can ask for a rematch; marks swap so the other player starts.

The computer opponent

  • Easy plays loosely and sometimes misses a block. Medium plays solid tactics with the occasional slip. Hard never loses at 3 × 3 and searches several moves ahead in caro.

Your record

  • Wins, losses and draws are counted on your account, with games against people and games against the computer kept separate.
  • Guests get a record too. Create an account and it moves with you.