Spasim (abbreviation of 'space simulation') was a 32-player 3D networked computer game by Jim Bowery involving 4 planetary systems with up to 8 players per planetary system, released in March 1, 1974. Jim Bowery claims that it is the very first 3D multiplayer game and has offered reward of US $500 to anyone who could document an example of a multiplayer 3D virtual reality game prior to Spasim. In Spasim the players flew around in space and to each other they appeared as wire-frame space ships. Their positions were updated about every second.

The game was played on the PLATO computer system, and was heavily influenced by another PLATO space multiplayer game Empire. Later 3D multiplayer games on the PLATO network included airace by Silas Warner that evolved into airfight (by Brand Fortner), and then spawned Panther by John Edo Haefeli at NW University. Atari, Inc had a PLATO account and Panther is said to be the origin of Battlezone while airfight led up to Sublogic's Microsoft Flight Simulator. Also, Panther was developed into the more sophisticated Panzer by the US Army.