First first-person shooter (FPS) videogame

The first ever first-person shooter (FPS) videogame was Maze War, developed by Steve Colley, Greg Thompson and Howard Palmer (all USA) in 1973, on the Imlac PDS-1's at the NASA Ames Research Center in California. It was eventually developed and innovated upon until it was released on DOS in 1992.

The game was initially designed as a technical showcase in which the player explored a 3D maze, showing off the vector graphics capabilities of the Imlac PDS-1 minicomputer. According to Steve Colley, this simple exploration game soon became boring, and so either Thompson or Palmer suggested the idea of putting additional players within the same maze, and from there it somehow developed into shooting at one another.

This required networking the Imlac computers, which were prior to this independent of one another. At this time it was just between two people, but Greg Thompson took a copy with him in 1974 to MIT, where he was going to study, and it was incorporated into the early ARPANET. An 8-player setup, AI controlled opponents, an overhead display monitor of the matches, and a level editor all soon followed. At one point in the mid-1970s, it is claimed that around half of all the data traffic on the ARPANET was related to Maze War games between students at MIT and Stanford University.

In 1976, multiple storeys were introduced to levels and the AI skill level became modifiable, due to the program having a dedicated machine for it. In 1977, a new version of the game was rewritten for Xerox's range of machines, which led to it becoming playable remotely via the Xerox Alto's ethernet network. Some programmers at PARC cheated by modifying their code so that they could see the positions of other players on the field map. This led to the authors of the code encrypting it to prevent this happening further. In 1986, it became the first game that could definitively be played across the internet (if 1983's SGI Dogfight's use of broadcast packets invalidates its chances).

Maze War's design and gameplay was enormously influential, providing the foundation for early dungeon crawlers like Wizardry and Phantasy Star.