Pocket Games
Tic Tac Toe
Tic tac toe is a solved game: if both players play well it always ends level. Which makes it perfect for exactly one thing — learning not to lose. The strategy fits in half a page, and once you have read it the bot’s hard level becomes an endless series of draws.
The rules
A 3×3 grid, two symbols, one symbol per turn in an empty cell. Whoever lines up three horizontally, vertically or diagonally wins. If the grid fills with no line, it is a draw.
On Pocket Games
Before starting you pick the mode: Vs Computer or Vs Player, two people on the same phone passing it back and forth. Who opens is drawn at random every game, and against the bot your symbol, X or O, is drawn at random too.
The bot has three levels, and each one chooses its move in a different way:
| Level | How it picks a move |
|---|---|
| Easy | any free cell, at random |
| Medium | wins if it can, otherwise blocks your win, otherwise prefers the centre, then corners, then edges |
| Hard | examines every possible game (minimax) and picks at random among the best moves |
Medium does not see double threats: it is the level where the fork described below works. Hard never loses, and when it can win it takes the shortest route.
- Under each level the start screen shows your wins, draws and losses against it. They stay on the device and are not synced to your account; two-player games do not count.
- The game in progress is saved after every move: when you come back you find the Game in progress card with mode, level and number of moves.
- There is no undo button.
The complete strategy
If you move first, play the centre. The centre belongs to four of the eight lines, corners to three, edges to two. It is the strongest cell on the grid, and opening there is the only start that gives you real winning chances against a distracted opponent.
If your opponent took the centre, take a corner. It is the only reply that does not lose. Answering on an edge hands your opponent a forced win.
If you move first and want to win, play a corner. Against a human opponent the corner opening creates the most traps: six replies out of eight lose, and their only salvation is taking the centre.
Priorities each turn, in this order:
- can you win in one move? win;
- can your opponent win in one move? block;
- can you create a double threat? create it;
- can they create one? prevent it;
- otherwise take the centre, then a corner opposite one of theirs, then an edge.
The double threat
This is how you beat someone who does not miss the obvious blocks. A move that creates two lines to complete at once: your opponent can only block one, and next turn you close the other.
The classic shape: two opposite corners yours, the centre theirs. If they reply on an edge instead of a corner, your next move gives you two open lines at once.
Hence the defence: when you see your opponent take two opposite corners, do not think about building — take an edge, which is the only move that defuses the fork.
Why it always ends level
Tic tac toe has 255,168 possible games, a number small enough to examine exhaustively. The result of that calculation is that with perfect play on both sides the game is a draw: no opening, not even the centre, forces a win.
That is why tic tac toe stops being interesting around the age of eight — and it is also why Tic Tac Toe Evolution exists, taking this grid and putting nine of them inside another, becoming an unsolved game again.
Frequently asked questions
Who starts the game?
The game draws it at random, one game at a time. Against the bot the symbol you get is random as well, so sometimes you open and sometimes the bot does.
Can the hard bot be beaten?
No. It works out every possible continuation and never leaves a win to its opponent: against it a draw is the ceiling. Medium, on the other hand, falls for double threats, and easy plays at random.
Can I resume a game I left halfway?
Yes. The game is saved after every move, both against the bot and with two players: when you reopen it, Game in progress appears and you pick up on the same grid.
Do my statistics follow me if I change phone?
No. Wins, draws and losses against the bot stay only on the device you played on, even if you use an account: tic tac toe has no online record.
More games to try
See the full list of games, or open Pocket Games in your browser: they are free and you don’t need an account.