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Tic-tac-toe for two: a grid that knows the rules

A tic-tac-toe grid for two people. Sit at one screen, pass a phone back and forth, or send a link after each move to someone far away. The page knows the rules: a square that has a mark takes no other, and the page says when a player has three in a row or when the grid is full and nobody has. There is no computer opponent, no clock, no account and no ads. Two people, and a game.

Private by design. The game is kept in one place only: the address of this page, after the # sign. Browsers do not send that part of an address to a website, so your moves never reach us. Nothing is saved on this device and nothing is sent. Whoever has the link can see the game and move in it, so send it only to the person you are playing. This page runs no analytics or tracking. How we handle privacy.

The rules, in plain words

The grid and the marks

The grid has three rows and three columns: nine squares.
One player marks X and the other marks O. On this page the two marks differ by shape, and also by colour.
The game starts with the grid empty.
On this page X always moves first. Then the players take turns, one mark a turn.
The game has other names: in much of the Commonwealth it is called noughts and crosses.

A move

A move is one mark of your own, put in an empty square.
A square holds one mark. A square that already has a mark, yours or the other player’s, cannot be marked again. The page says which squares are still empty.
Once made, a mark never moves and is never rubbed out.
There is no skipping a turn.

How a game ends

A win: the first player to have three of their own marks in one straight line wins. The line can be a row, a column, or one of the two diagonals.
The game stops there. The page marks the three squares and takes no more moves.
A draw: if all nine squares are full and nobody has three in a row, nobody wins.
A game lasts nine moves at most, and nobody can have three in a row before the fifth mark.
A player may also give up. The page has no button for that: say it out loud and press “New game”.

Playing with someone far away

Make your move, then press “Copy a link to this game” and send the link by text, email or any messenger.
The other person opens the link, sees the grid as you left it, makes a move, and sends their link back.
It is not live: a move does not show up on the other screen by itself. The newest link is the game.
The page cannot know who made a move. Anyone holding a link can move for either side, or take a move back.
Who plays X? Pick for us can toss a coin.

How the rules were checked

One way to test a program that knows a game is to count. For this game the counts are published, and a program with a rule wrong gets a different number.
Each time this page is built, a program plays out every game this page would allow, from the empty grid to the end, and counts them: 255,168 games. That is the published number (sequence A061526 in the On-Line Encyclopedia of Integer Sequences). The count comes out right only if the page stops a game at three in a row.
The same program counts the different positions after each number of marks, counting a grid and its turned or flipped copies once, 765 in all (sequence A008907), and the positions where a game is over, 138 in all (sequence A048245). Of those 138, it finds 91 won by X, 44 won by O and 3 drawn, the numbers Wikipedia’s article on the game gives. The build stops unless every count is equal. The three sequences and the article were fetched on October 14, 2026.
It also checks a set of small positions we made ourselves: a taken square, three in a row, in a column and on each diagonal, two that is not three, a row broken by the other mark, three marks that are not in one line, a full grid with no three, a full grid with two lines of three, and two drawn games from Wikipedia’s article.
The rules explained on this page are our own wording, compared with that article. They were not checked by a referee, and Scarlet Beast has no tie to either website.

What this page can’t do

It does not play. There is no computer opponent and no AI in it, and it never suggests a move.
It does not keep your game. The game lives in the address of the page. If the page is closed and the link is lost, the game is gone, and we cannot give it back, because we never had it.
It has no clock, no score over many games and no list of players. Keep the score on paper if you like.
It knows one grid. This page has the three-by-three grid and the plain game only. For a bigger board where the marks fall, there is Four in a row for two.
It is not an official rulebook. Wikipedia’s article says there is no rule everyone agrees on about who plays first. If you play for something that matters, agree on the rules before you start.
It was tried by a program in one browser, with a mouse and a keyboard. It has not been tried on a touch screen or with a screen reader.

Pages that go with this

Four in a row for two, Reversi for two, Checkers for two and Chess for two: the same kind of board, for those games.
Games and puzzles: these five boards and eight more pages for play (sudoku, mazes, bingo cards, crosswords and more) on one list.
Pick for us: a coin, dice, or a name out of a hat, to decide who plays X.
Visual timer: if you want a time limit for a move.
All the free tools, and how to save them on your phone.

A game, and nothing more. A game can be good company in a long hour, and it cannot do more than that. If things are heavier than a game can hold, Get help now lists people to call. If you are thinking about ending your life, call or text 988 (in the U.S.). If anyone is in danger, call 911.

The tool and the wording on this page were written with AI (Claude) for Scarlet Beast (our AI policy). There is no AI inside this tool: it knows the rules and nothing else, and it never picks a move. It has been checked by a program, with a mouse and a keyboard in one browser; no person has read it through or played a game on it yet, and the Spanish of the page has not been read by a native speaker. It keeps nothing, so it has no line on My data on this device. Also in Spanish: Tres en línea para dos. Found a mistake? Email [email protected].