Entombed | 1982

Entombed

Entombed (Atari 2600)

Entombed is a game designed by Tom Sloper and programmed by Steven Sidley for the Atari 2600, released by US Games in 1982. The game centers around a player navigating through an endlessly scrolling maze, avoiding enemies that cross the screen. Its intricate maze-generation algorithm has been a subject of academic study.

The player moves downward through a vertically scrolling maze while avoiding enemies that move across the screen. If the player touches a monster, the monster kills them, ending the game. The maze continually scrolls upward, and while the player can move in any direction, this movement can sometimes trap them in dead ends. The player must collect "escape" items, represented as large dots, which allow them to remove wall sections and escape dead ends. In 2-player mode, both players are in the maze simultaneously.

The mechanism for how Entombed generates its mazes has been the subject of academic research and legend, as the maze data would have been too large to store directly, even with the symmetry. Researchers discovered that the maze is generated on the fly, based on the adjacent five squares' status (either a wall or open space), using a lookup table to determine the next section, which sometimes includes random states. This occasionally leads to unsolvable mazes unless a "make-break" entry is involved.

Steven Sidley mentioned that the algorithm came from an anonymous programmer who, according to Sidley, thought of it while intoxicated. Later studies suggested this might have been a story devised to avoid explaining the algorithm or assigning intellectual property rights. A 2021 paper described generalizing the algorithm to 3D mazes, and in 2022, a publication co-authored by Paul Allen Newell, who worked on the game, further clarified the mystery behind the maze algorithm.