2048 (video game)

2048 is played on a plain 4×4 grid, with numbered tiles that slide when a player moves them using the four arrow keys. If a move causes three consecutive tiles of the same value to slide together, only the two tiles farthest along the direction of motion will combine. If all four spaces in a row or column are filled with tiles of the same value, a move parallel to that row/column will combine the first two and last two. A scoreboard on the upper-right keeps track of the user's score. The user's score starts at zero, and is increased whenever two tiles combine, by the value of the new tile. When the player has no legal moves (there are no empty spaces and no adjacent tiles with the same value), the game ends. Strategy Strategies in 2048 include keeping the largest tile in a specific corner with other large tiles filling the row (either vertically or horizontally). If the row remains filled, the player can then move in three different directions while still keeping the largest tile in the preferred corner. As a general rule, no small tiles should be separated from other small tiles by a large tile. == Development ==

Nineteen-year-old Gabriele Cirulli created the game in a single weekend as a test to see if he could program a game from scratch. "It was a way to pass the time", he said. and a clone of another game, 1024. 1024 is itself a clone of Threes, with its App Store description once reading "no need to pay for Threes". Cirulli was surprised when his weekend project received over 4 million visitors in less than a week. The game is free to play, Cirulli having said that he was unwilling to make money "from a concept that [he] didn't invent". He released ports for iOS and Android in May 2014. Adaptations using the curses library|alt=2048 The simple controls allowed it to be used in a promo video for the Myo gesture control armband, and the availability of the code underneath allowed it to be used as a teaching aid for programming. As the source code is available, many additions to the original game, including a score leaderboard, an undo feature, and improved touchscreen playability have been written by other people. All are available to the public. Spinoffs have been released online and include versions with elements from the Doge meme, Doctor Who, Flappy Bird and Tetris. There has also been a 3D version Cirulli sees these spinoffs as "part of the beauty of open source software" In 2014, an unofficial clone of the game was published in the iOS App Store by Ketchapp, monetized with advertising. An unofficial clone was also released for the Nintendo 3DS. In the decade following its initial release, the game's open-source codebase continued to be optimized for high-performance web environments. By 2026, these modern iterations, which frequently include features such as cross-device save synchronization and global leaderboards, have become staples on major web gaming portals including Poki and CrazyGames, ensuring the title's continued availability across diverse hardware platforms without the need for dedicated mobile application downloads. == Reception ==

The game has been described by The Wall Street Journal as "almost like Candy Crush for math geeks", and Business Insider called it "Threes on steroids". When asked if he was concerned that his situation would end up as stressed as that of Nguyễn Hà Đông, the creator of Flappy Bird, Cirulli said that he had "already gone through that phase" on a smaller scale, and that once he had decided against monetizing 2048, he "stopped feeling awkward." In response to rampant cloning, the creators of Threes published a log of how the game evolved over its 14-month development cycle. They said they had tried and dismissed 2048 tile merging variant, because it made the game too easy. In a 2014 Wired article, they claimed to have each beaten 2048 on their first play. == Use in artificial intelligence research ==

The mathematical nature of 2048 has made the game of interest to researchers of artificial intelligence. As of 2022, AI achieved over 95% (likely over 98%, but the measurement has noise) probability of making a 16384 tile, over 75% (likely over 80%) probability of making a 32768 tile, and over 3% probability of making a 65536 tile (improving over the results in previous papers). Due to randomness and lack of spare room, the optimal probability of making a 65536 tile is expected to be low; this is supported by optimal solutions for constrained boards. Recent benchmarks in early 2026 have explored the use of transformer-based neural networks to predict tile placement probabilities, further narrowing the gap between heuristic-based solvers and optimal play. 2048 AI strategy uses expectiminimax search up to a certain (variable) depth, plus transposition tables to avoid duplication. Analogously to endgame tablebases, tables are used to estimate success (for building a large enough tile without destroying the configuration) in appropriate positions with many large tiles. A position evaluation function can favor empty squares, having a large number of merge possibilities, placement of larger tiles at the edge, and monotonicity for tile sizes, especially for larger tiles. The parameters are optimized by a search for better parameter values; some papers used temporal difference reinforcement learning. ==References==