ArcadeLime

Game guides

Tic Tac Toe: create and answer a fork

A fork creates two different winning threats. Check for an immediate win or a move you must block before trying to create one.

Play the game

Worked example

Choose Two Players and Classic. Play X1, O5, X9, O3, X7. X now threatens square 4 to complete 1–4–7, and square 8 to complete 7–8–9. O cannot block both in one move. Try O4, then X8: the bottom row wins. The screenshot shows the position before O chooses a reply.

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  2. 2
  3. 3
  4. 4
  5. 5
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  7. 7
  8. 8
  9. 9
Tic Tac Toe: create and answer a fork — Example from the current ArcadeLime game
Example from the current ArcadeLime game

Try this

  1. Number the board 1–9 in reading order.
  2. Reproduce the five moves in the example.
  3. Change the fourth move of the sequence (O's second move) and check whether X still has the same fork.

Common mistake

Two marks in a line are one threat. A fork needs two separate winning moves. Always check the opponent's immediate win first.

Practice

Restart the round and take O's side. Look for a reply that prevents the fork before X places the fifth move.