2048

Mechanics worth knowing precisely

Every move slides all tiles in one direction; equal neighbors merge into their sum, and each tile can merge only once per move. When a line holds three equal tiles, the pair nearer your swipe direction merges and the leftover stays, so pushing left on 2 2 2 gives 4 2, not 2 4. Your score increases by the value of every tile created by a merge, meaning a 2048 tile pays 2048 points at the moment of its creation, plus everything earned building it. After any move that changes the board, a new tile appears in a random empty cell: 90 percent of the time a 2, 10 percent a 4, the original game's odds. A swipe that changes nothing is rejected and spawns nothing. The game ends only when the board is full and no adjacent equals remain; reaching 2048 is a milestone, not an ending.

The undo button reverses exactly one move, including the random tile it spawned, and cannot chain backward. It even works on the move that ended your game, which makes it a genuine safety net rather than a decoration.

Strategy that survives past 512

Pick a corner and swear allegiance to it. Keep your biggest tile there and build a descending chain along that edge, which in practice means using only three of the four directions and treating the fourth as an emergency you will regret. The board dies when big tiles wander into the middle, because everything that could merge with them is an order of magnitude smaller.

Here is the tip most guides skip: use your undo on spawns, not on slides. The one-step undo reverts the random tile along with your move, so when a forced move drops a fresh tile into your corner lane at the worst spot, undoing and choosing a different direction re-rolls both the choice and the randomness. It is a limited weapon, one step only, but spent at the right moment it converts several percent of lost games into wins. Also learn to count spawn risk before a risky swipe: with the 90/10 rule, that gap you are about to open will usually receive a 2, and your plan should survive a 4.

What scores mean here

Reaching the 2048 tile lands your score in the neighborhood of 20,000, since the score is the accumulated cost of building every tile along the way. The biggest-tile box is often the more honest bragging metric: 512 means competent, 1024 means disciplined, 2048 means you kept a corner strategy intact under pressure, and 4096 or beyond means you have internalized the spawn odds. Best score is saved in your browser, and undo makes runs here slightly easier than strict no-undo play, which is worth admitting if you compare records with a purist.

Design notes

Controls are arrow keys, WASD, or swipes of at least 24 pixels on touch screens, and the swipe direction is judged by the dominant axis, so diagonal-ish swipes still resolve cleanly. Spawn placement is uniformly random over the empty cells; the game never places tiles adversarially, even when it feels personal. There is no animation-based sleight of hand in the merge logic, no timer, no leaderboard, and no monetized continue. When the board locks, the run is over unless that one undo is still unspent.