# Win at Tic Tac Toe

Tic Tac Toe, also known as *"Noughts and Crosses"* or *"X's and O's"*, is a solved game. This means there is a known, mathematically proven strategy to follow for the best result each game. In Tic Tac Toe, two players who follow the right strategy will always tie, with neither player winning. Against an opponent who doesn't know this strategy, however, you can still win whenever they make a mistake. Once your friends pick up on your strategy, try a more difficult version of the rules.

If you don't know how to play tic tac toe, learn the Play-Tic-Tac-Toe.

## Contents

## Samples

Doc:Tic Tac Toe Strategies,Tic Tac Toe Game

## Steps

### Winning or Drawing when Playing First

- Play your first X in a corner. Most experienced tic tac toe players put the first "X" in a corner when they get to play first. This gives the opponent the most opportunities to make a mistake. If your opponent responds by putting an O
*anywhere*besides the center, you can guarantee a win.^{[1]}- In this example, you are going first, and using X as your symbol. Your opponent goes second, and uses O.

- Try to win if your opponent plays the first O in the center. If your opponent plays her first O in the center, you have to wait for her to make a mistake before you can win. If she continues to play correctly, she can guarantee a tie. Here are your two options for your second move, followed by instructions on how to win if she makes certain moves (if she doesn't, just keep blocking her plays and the game will be a tie):
- Place your second X in the opposite corner from your first, so there's a line going "X O X" diagonally across the board. If she responds with an O in one of the other corners, you can win!
^{[1]}Place your third X in the last empty corner, and your opponent won't be able to block you from winning with your fourth X. **Or**, place your second X on an edge square (not a corner),*not*touching your first X. If your opponent puts down an O in the corner that's*not*next to your X, you can use your third X to block her move and automatically win with your fourth X.

- Place your second X in the opposite corner from your first, so there's a line going "X O X" diagonally across the board. If she responds with an O in one of the other corners, you can win!
- Win automatically if your opponent plays his first O in any square besides the center. If your opponent puts his first O in any square
*besides*the center, you can win. Respond by putting your second X in any other corner, with an empty space in between the two X's.- For example, say your first X is in the top left square, and your opponent puts an O in the top middle square. You can put your second X in the bottom left corner, or the bottom right corner. Don't put it in the top right, since that would put an O between your two X's instead of an empty space.

- Place your third X so you have two possible winning moves. Most of the time, your opponent will see that you have two X's in a row and block you. (If not, just win by making a row of three X's.) After this happens, there should be an empty square that is in line with both your first and your second X, with no enemy O's blocking that line. Put your third X in this square.
- For example, take a piece of paper and draw a tic tac toe board with the top row "X O _", the middle row "O _ _," and the bottom row "X _ _." If you place your third X in the bottom right corner, it's in line with both of your other X's.

- Win with your fourth X. After your third X, there are two empty squares that will win you the game if an X goes into one of them. Since your opponent can only make one move, he can only block one of those squares. Write your fourth X into the square he didn't block, and you've won the game!

### Never Losing when Playing Second

- Force a draw if the opponent starts in the corner. If the opponent plays first and starts with an O in a corner, always put your first X in the center. Your second X should be placed on an edge,
*not*a corner,*unless*you need to block your opponent from getting three in a row. Using this strategy, every game should be a draw.^{[1]}Theoretically, you can win from this position, but your opponent would have to make a huge mistake, such as not seeing that you have two X's in a row.- In this section, your opponent is still playing O's, but remember she gets to play first this time.

- Force a draw when the opponent starts in the center. When your opponent starts by putting down an O in the center, place your first X in a corner. After that, just keep blocking your opponent from scoring and the game will be a draw.
^{[1]}There is essentially no way for you to win from this position, unless your opponent stops trying to win or stop you from winning! - Try to win if the opponent starts at the edge. Most of the time, your opponent will start with one of the moves above. However, if your opponent puts down the first O on an edge, not on a corner or center, you have a small chance to win. Put your first X in the center. If your opponent puts the second O on the opposite edge, making a row or column that reads O-X-O, put your second X in a corner. Then, if your opponent puts the third O in the edge that is adjacent to your X, making a line that reads O-X-O, put your third X in the empty square to block their row of two O's. From here, you can always win with your fourth X.
^{[1]}- If at any point, your opponent doesn't make the exact move described above, you'll have to settle for a draw. Just start blocking their moves and neither of you will win.

### Tic Tac Toe Variations

- Try these out if your tic tac toe games always end in draws. It might be fun for a while to be unbeatable at tic tac toe, but even without this article your friends might figure out how to stop you from winning. Once that happens, every single game of tic tac toe you play with them will be a draw — ugh. But you can still use basic tic tac toe rules to play games that aren't as easily solved. Try them out below.
- Play mental tic tac toe. The rules are exactly the same as tic tac toe, but there's no board! Instead, each player says her moves aloud, and pictures the board in her head. You can still use all the strategy advice in this article, but it can be difficult to concentrate on that when you're trying to remember where the X's and O's are.
- Agree on a system for describing moves. For instance the first word is the row (top, middle, or bottom) and the second word is the column (left, middle, or right).

- Play 3D tic tac toe. Draw three tic tac toe boards on separate pieces of paper. Label one board "top," another "middle," and the third board "bottom." You can play anywhere on these boards, and they work as though they were stacked on top of each other to make a cube.
^{[2]}For instance, taking the center on all three boards wins you the game, since it makes a line standing vertical through the cube. Getting three in a row on any single board also wins. See if you can figure out how to win with a diagonal line across all three boards.- For a real challenge, combine this with the last variation and try mental 3D tic tac toe. The first word is the board (top, middle, or bottom), the second word is the row (top, middle, or bottom), and the third word is the column (left, middle, or right).

- Play five in a row. Play this game, sometimes called Gomoku, on a piece of graph paper, without even having to draw a board. Instead of marking X's and O's inside the squares, write them at the intersections where the graph paper lines meet. You can make each move anywhere on the graph paper. The first player to get exactly five in a row (not six or more) wins the game.
^{[3]}This game is surprisingly complicated, despite its similarity to tic tac toe, and even has world championship tournaments.^{[4]}- In tournaments, players use a 15x15 or a 19x19 board, but you can use any size of graph paper for this game. You could even play on an infinite board, taping on more graph paper whenever you need to.

## Tips

- Against a novice opponent, try this challenge. Go first and play the first X on the edge. You can only guarantee a win if the opponent's first O is on a corner not touching your X,
*or*on an edge that*is*diagonal to your X.^{[5]}Can you figure out how to win in these two situations? - For an even harder challenge, try to win after you go first and put an X in the center. If the opponent puts the first O on an edge (which rarely happens), you can guarantee a win.
^{[6]}Can you figure out how? - There are other solved games that one player can always win, even if all players play optimally (correctly). For instance, in Connect Four, the first player can always win if he follows the right strategy.
^{[7]} - Be careful with your moves and think in advance.

## Warnings

- Even someone who doesn't know these strategies will catch on quickly if you start from the same position each side. Even if you are practicing starting at the corner, for instance, try starting from different corners so it takes them longer to figure out the pattern.

## Related Articles

- Memorize a List Using Numbers and Rhyming Words
- Calculate Your Name Number in Numerology
- Play Rock, Paper, Scissors
- Whistle With Your Fingers

## Sources and Citations

- ↑
^{1.0}^{1.1}^{1.2}^{1.3}^{1.4}http://www.cs.jhu.edu/~jorgev/cs106/ttt.pdf - http://www.math.cornell.edu/~mec/2003-2004/graphtheory/tictactoe/howtoplayttt.html
- http://gomokuworld.com/gomoku/1
- http://gomokuworld.com/worldchampionship
- http://www.novelgames.com/en/gametips/tictactoe-win/
- http://www.novelgames.com/en/gametips/tictactoe-win/
- http://www.informatik.uni-trier.de/~fernau/DSL0607/Masterthesis-Viergewinnt.pdf