2048

2048 is a single-player sliding puzzle game played on a 4x4 grid. Numbered tiles slide across the board when the player swipes in a direction (up, down, left, or right). When two tiles with the same number collide, they merge into one tile with their sum. A new tile (usually 2, occasionally 4) appears in a random empty cell after each move. The goal is to create a tile with the value 2048, though play can continue beyond that to achieve even higher scores.

Rules

1. The game starts with two tiles (valued 2 or 4) placed randomly on a 4x4 grid.
2. The player swipes in one of four directions: up, down, left, or right.
3. All tiles slide as far as possible in that direction.
4. If two tiles with the same number collide during a slide, they merge into one tile with double the value.
5. A tile can only merge once per move (a merged tile does not merge again in the same move).
6. After each move, a new tile (90% chance of 2, 10% chance of 4) appears in a random empty cell.
7. The goal is to reach the 2048 tile. The game ends when no more moves are possible (the grid is full and no adjacent tiles can merge).

Scoring

• Each merge adds the value of the new tile to the score.
• Merging two 2s scores 4 points, two 4s scores 8, two 1024s scores 2048, and so on.
• The theoretical maximum tile is 131,072 (2^17), though reaching it is astronomically unlikely.

Strategies

• Corner Strategy: Keep your highest-value tile in one corner (typically bottom-left or bottom-right). Build a descending sequence along the edge leading to that corner.
• Avoid Moving Against Your Anchor: If your highest tile is in the bottom-left corner, avoid swiping up or right unless absolutely necessary, as this can dislodge it.
• Build Monotonic Rows: Keep tiles in a row in ascending or descending order. This allows chain merges when new tiles arrive.
• Manage the Second Row: Once the bottom row is arranged, work on building the second row in reverse order. Think of it as a snake pattern: bottom row left-to-right, second row right-to-left.
• Keep the Board Clear: Avoid filling up the board. The more empty cells available, the more room you have to maneuver. Make merges as quickly as possible.
• Plan Ahead: Before swiping, consider not just the immediate merge but where new tiles will appear and whether the resulting board state is manageable.

2048 was created by Gabriele Cirulli, a 19-year-old Italian web developer, in March 2014. Cirulli built the game over a single weekend using JavaScript and published it as a free, open-source project on GitHub. The game went viral almost immediately, attracting millions of players within days of its release and becoming one of the most-shared web games of the 2010s.

Cirulli openly acknowledged that 2048 was inspired by two earlier games. The first was "1024" by Veewo Studios, a similar sliding tile game. The second, and more direct inspiration, was "Threes!" by Sirvo LLC (created by Asher Vollmer and Greg Wohlwend), which was released in February 2014, just one month before 2048. Threes had been in development for over a year and featured a more nuanced merging system. The developers of Threes publicly expressed mixed feelings about 2048's sudden popularity, as their carefully designed game was overshadowed by a simpler derivative that was free to play.

Despite the controversy, 2048's impact was enormous. Being open-source, it spawned hundreds of variants: 3D versions, hexagonal grids, multiplayer modes, AI solvers, and themed versions (including versions with Doge memes, which contributed to its viral spread). The game's simplicity — learnable in seconds but difficult to master — made it universally appealing. It was ported to iOS and Android, where it accumulated hundreds of millions of downloads across various versions.

From a mathematical and AI perspective, 2048 has been extensively studied. Researchers have developed AI agents using techniques including minimax with alpha-beta pruning, expectimax algorithms, Monte Carlo tree search, and deep reinforcement learning. These agents can consistently reach the 2048 tile and occasionally achieve 8192 or even 16384. The game's state space has been analyzed, revealing that about 2% of random games naturally produce the 2048 tile, while optimal play reaches it nearly 100% of the time. The game remains a popular benchmark for AI research and a beloved casual game worldwide.