20482048 rules
Slide the tiles, merge equal numbers, and build the biggest tile you can. The rules are the classic game's; the duel adds one twist: both players get exactly the same tiles.
The board
A 4×4 tray that starts with two tiles. Every tile is a power of two: 2, 4, 8, 16 and up.
A move
- Swipe (or press an arrow key, or W A S D) to slide every tile as far as it goes in that direction.
- Two equal tiles that meet merge into one tile of double the value. The new tile's value is added to your score: merging two 64s scores 128.
- A tile merges at most once a move.
- Every move that changes the board brings one new tile: a 2 nine times in ten, a 4 otherwise, on an empty cell.
- A swipe that changes nothing is not a move: no tile comes and nothing is counted.
How a game ends
- The game is over when the board is full and no two neighbouring tiles are equal: no move would change anything.
- In Classic, making the 2048 tile is the goal. You can keep going after it.
The Same tiles duel
Same tiles, 250 moves, 3 minutes. Best score wins.
- Both players play the same secret seed at the same time, each on their own board: the n-th new tile has the same value for both, and lands in the same place whenever that cell is free on both boards.
- Each player has 250 moves and 3 minutes on their own clock. You play in parallel: nobody waits for anybody.
- Your run ends at your 250th move, at 0:00, or when you have no move left, whichever comes first. Your score at that moment stands.
- The higher score wins. If the scores are level: the higher best tile; then fewer moves used; then less time used. If everything is level, it is a draw.
- After the same number of moves both boards hold exactly the same total, so the score measures only how well you merged it.
- There is no undo in a duel.
Practice
- Classic: endless, unlimited undo (counted), your best score and best tile kept on this device.
- Versus the ghost: the duel's format against our own bot at three levels. It plays the same tiles at a human pace and never sees the seed: like you, it only sees its board.
- Leaving a Classic game keeps it: come back and it is exactly where you left it.
Questions
Is undo allowed?
In Classic practice, yes, as often as you like. Undo takes back the board, the score and the tile that came, so the same tile comes again: it can never reroll a bad one. Your undos are counted on your result. A duel has no undo.
Where do new tiles come from?
After every move that changes the board, one tile appears on an empty cell: a 2 nine times in ten, a 4 otherwise. On Ariplex the tiles come from a seed (a 32-character number) through a published generator, so a game can be replayed exactly from its seed and its moves.
What happens when I make 2048?
In Classic you get the moment, then you can keep going for 4096 and beyond. In a duel 2048 is just a big tile: the score decides.
Why both a move limit and a clock in a duel?
250 moves in 3 minutes is under one and a half moves a second, an easy swipe pace, so speed beyond it buys nothing and a phone is as good as a keyboard. The clock stops anyone stalling or looking every move up.
Can I see my opponent's board?
No, only their score, moves and best tile while you play, and the gap between you at the same number of moves. A player who is ahead in moves would otherwise show the other the tiles to come. Both boards and the full replay are shown after the game.
How do I know the tiles were fair?
Before the game the server shows a seal: the SHA-256 hash of "2048:", the match id, ":" and the seed. After the game it shows the seed. Hash it yourself and compare; then replay both runs from the seed. The seal proves the tiles were fixed before either of you moved, and that you both had the same ones.
Does my phone report my score?
No. Your phone sends only your moves. The server plays each one itself on its own copy of the board, and the score is the server's.
Do looks change anything?
No. Every tile set plays the same; the default flat set is the easiest to read.