How to play 2048

The sliding number puzzle, made a fair head-to-head contest: both players get exactly the same tiles.

Setup

A 4×4 tray with two tiles. Every new tile is a 2 nine times in ten and a 4 otherwise, drawn from a seed sealed before the game.

On your turn

• Swipe (or press an arrow key) to slide every tile as far as it goes.
• Two equal tiles that meet merge into one of double the value, and that value is added to your score. A tile merges at most once a move.
• Every move that changes the board brings one new tile. A move that changes nothing is not a move.

Special rules

• In a duel both players play the same sealed seed at the same time: the same tile values in the same order, landing in the same place whenever that cell is free.
• Each player has 250 moves and 3 minutes; a run ends at either limit, or when no move is left.

Winning, draws and losing

• Practice: play on as long as you can; making the 2048 tile is the classic goal.
• Duel: the higher score wins; then the higher best tile; then fewer moves used; then less time used. A dead level duel is a draw and refunds both stakes.

Online rules and fair play

• Your device never reports a score: the server plays every move itself from the sealed seed, so a score cannot be faked.
• The seed's SHA-256 seal is published before the game and the seed after it, so anyone can replay both runs and check both players had the same tiles.
• You see your opponent's score and moves as you play, never their board.