Tic Tac Toe

Tic Tac Toe (also:. Three wins, XXO, circle and cross, Dodelschach Noughts and Crosses or English ) is a classic, simple two-person strategy game whose history can be traced back to the 12th century BC.

Game History

On a square, 3 × 3 squares large playing field, the two players take turns placing their characters (one player crosses the other circles) in an open field. The player who can put the first three characters in a row, column or diagonal wins. However, if both players play optimally, no one can win, and it comes to a draw. This means that all nine squares are filled, without any player could set the required characters in a row, column or diagonal.

Sample games

First player (X) wins because players makes a mistake two (O) in the first round:

First player (X) wins because players makes a mistake two (O) in the first round:

First player (X) loses because he makes a mistake in the second round:

No player wins, because both play flawlessly:

Strategy and tactics

For Tic Tac Toe, there are 255 168 different game histories, of which 131 184 end with a victory on the first player, 77 904 with a victory of the second player, and 46,080 with a draw. ( In these figures, the first configuration with three X's or three O in a row, column or diagonal or a completed field but not been the situation from which it is clear the output, seen as the end of the game. )

Many game histories are equal in the sense that they can be converted by rotations or reflections of the field together. Summarized the same courses, the number of different game histories reduced to one-eighth: a total of 31 896, with 16,398 to be won by the first and second player from the 9738 and 5760 end with a draw. (From Every Game History is obtained by rotations and reflections seven other game histories, because there at the end of at least five fields are always busy, no gameplay is symmetric with respect to rotation or mirroring. )

There are 5,478 different game situations without rotation or reflection 765 Compared to games like Go, checkers or chess, the number of game histories and game situations is negligible. Because of this low complexity can be easily shown that both players can force a draw.

The first player can not lose in the first train. The second player has a draw in only 24 of the 72 possibilities for the first two trains.

First player (X) starts second player (O) holds a draw (mirrored and rotated options are not shown):

There are 16 draw - positions, which can be obtained from the following three by mirroring or rotation:

In most cases the first player uses (X ) into the center. The second player has to force a draw, put in the corner, otherwise player 1 can effortlessly achieve a victory:

More information

Tic Tac Toe was also one of the first games that appeared on computers ( before Tennis for Two, 1958) ( game OXO on a EDSAC computer, 1952).

A crucial role is played Tic Tac Toe in the movie Wargames.

Tic Tac Toe ran in 1992 as a daily game show on RTL. Moderator was Michael Förster. There, hidden behind each of the fields a question to be answered in four seconds; it won, who has conquered the first one triple row of windows.

The game was also the basis for the U.S. game show Hollywood Squares, which in the 90s as XXO in Germany - Fritz and Co ran at Sat.1.