The first networked games
Spacewar! (1962) was played on a single PDP-1 at MIT. Within a decade, variants were running on computers connected to ARPANET — the US Defense Department network that preceded the commercial internet — and being played across institutions. This was informal, technically demanding, and accessible only to researchers and students at connected universities. The barrier to entry was graduate-level computer access, not consumer hardware. But the instinct was immediate: as soon as computers could communicate, people played games across them.
The first game purpose-built for networked play was probably Maze War, developed at NASA's Ames Research Center in 1973–74, which allowed players at different computers on a local network to navigate a first-person maze and shoot each other. MUD — Multi-User Dungeon — was written by Roy Trubshaw and Richard Bartle at the University of Essex in 1978. MUD1 was a text-based RPG that allowed multiple players to explore a shared world simultaneously over the ARPANET. Bartle and Trubshaw gave free access to other universities. By the early 1980s, dozens of universities had MUD servers running, and thousands of players had experienced the specific thing that networked games offered that single-player games couldn't: other people, unpredictable and present, sharing the same space.
BBS door games
Bulletin Board Systems — BBSs — were computers running software that allowed other computers to connect via phone modem, upload and download files, and exchange messages. By the mid-1980s, tens of thousands of BBSs operated across North America, most run by hobbyists, most accessible via local phone calls. A BBS that hosted games outside its normal software — accessible through a menu option called a "door" — hosted what became known as door games.
Door games were not real-time multiplayer in the way that later online games would be. A BBS typically served one caller at a time, which meant door games were turn-based and asynchronous. A player would take their turn, leave the game, and return the next day to see how other players had responded. TradeWars 2002 (1984, expanded through the late 1980s) was a space trading and combat game in which players competed for resources across a shared galaxy, with the game world persisting and updating between sessions. Legend of the Red Dragon (1989) was an RPG with light social features — players could marry each other, leave messages, fight each other for dominance. These games were designed around the BBS's constraints and used them deliberately: the daily play limits, the asynchronous turns, the public posting of results created a community structure around the game.
At their peak in the early 1990s, BBS door games had millions of players across North America. They were the first games that most players experienced where other humans were present in the game world — as named characters, competitors, or allies — even if that presence was asynchronous rather than simultaneous.
The commercial online services
CompuServe, GEnie, and later America Online offered dial-up access to online services before the public internet existed. These were expensive by later standards — GEnie charged per minute during peak hours — and technically limited, but they supported multiplayer games that were genuinely real-time: multiple players in the same session simultaneously.
Island of Kesmai launched on CompuServe in 1984 and is often identified as the first commercially available online RPG. It was text-based and ASCII-rendered, playable in real time with other subscribers, and charged by the hour. A dedicated player could spend hundreds of dollars a month. The player base was small but intensely engaged — people who were willing to pay premium rates for the experience of a shared persistent world.
Neverwinter Nights — not the 2002 BioWare game of the same name, but a 1991 game on AOL by Stormfront Studios — is generally identified as the first graphical MMORPG. It used the same engine as the SSI Gold Box D&D games, displayed in EGA graphics, and supported up to 50 simultaneous players per server. At its peak in 1997, it had 115,000 subscribers. Each paid AOL's hourly rate on top of their subscription. The business model was wildly profitable per engaged player. It also limited scale: the games that could be commercially viable were those with a user base willing to pay ten to fifteen dollars per hour of play time, which meant a self-selecting audience of committed enthusiasts.
Habitat and the invention of the virtual world
Habitat, developed by Lucasfilm Games in 1986, was different from everything that preceded it. It was graphical — characters were represented as customisable avatars, not text labels. It was designed around social interaction as its primary purpose, not combat or trading. And it was designed to be a persistent world that existed and changed independent of any particular player's session — a virtual space rather than a game with explicit win conditions.
The designers, Chip Morningstar and Randy Farmer, wrote a paper about their experience building Habitat that became one of the foundational documents of online world design. Their central observation was that a virtual world with many participants would generate emergent social structures, economies, crimes, and conflicts that the designers had not anticipated and could not fully control. Players in Habitat organised religions, established newspapers, created laws, elected sheriffs, and — in one famous incident — used an oracle mechanic to obtain massive amounts of currency, destabilising the virtual economy. Morningstar and Farmer's response to each crisis was to intervene as little as possible and treat the player community as capable of self-governance.
Habitat never scaled beyond its test population. Technical and commercial constraints prevented the kind of deployment that would have made it a mass-market service. But the design principles Morningstar and Farmer articulated — emergent social behaviour, minimal designer intervention, the economy as a game element — appeared in every successful MMORPG from Ultima Online (1997) onward. The genre they were inventing didn't reach mass audiences until a decade after they invented it, and when it did, it rediscovered their conclusions independently.