The university's computer system had hundreds of terminals, connected (via serial lines) through cluster PDP-11s for student, teacher, and staff access. The first large-scale serial sessions using a single computer were STAR (based on Star Trek), OCEAN (a battle using ships, submarines and helicopters, with players divided between two combating cities) and 1975's CAVE (based on Dungeons and Dragons), created by Christopher Caldwell (with artwork and suggestions by Roger Long and assembly coding by Robert Kenney) on the University of New Hampshire's DECsystem-1090. The games had broader consoles to allow for four sets of controls.
Gauntlet (1985) and Quartet (1986) introduced co-operative 4-player gaming to the arcades. Danielle Bunten Berry created some of the first multiplayer video games, such as her debut, Wheeler Dealers (1978) and her most notable work, M.U.L.E. All players' scores are often displayed onscreen so players can see their relative standing. In such games, play is alternated at some point (often after the loss of a life). Other early video games included turn-based multiplayer modes, popular in tabletop arcade machines. Multi-user games developed on this system included 1973's Empire and 1974's Spasim the latter was an early first-person shooter. The first examples of multiplayer real-time games were developed on the PLATO system about 1973. Some of the earliest video games were two-player games, including early sports games (such as 1958's Tennis For Two and 1972's Pong), early shooter games such as Spacewar! (1962) and early racing video games such as Astro Race (1973).