The Untold History of How the First Online Multiplayer Game Connected Players Through Phone Lines

The Untold History of How the First Online Multiplayer Game Connected Players Through Phone Lines

In 1973, a computer scientist at the University of Illinois sat down to play a space shooter with another person across campus. Neither of them knew it, but they were about to kick off a revolution that would eventually lead to 100 million people playing Fortnite in a single night. The game was Empire, and it ran on something called PLATO—a system that worked entirely through phone lines long before the internet existed.

The PLATO System: A Computer Before Computers

To understand Empire, you need to understand PLATO (Programmed Logic for Automatic Teaching Operations). Built by the University of Illinois with funding from the National Science Foundation, PLATO was originally a teaching mainframe. But its designers made a wild decision: they gave every terminal a plasma display, a touchscreen, and a connection to a central computer over 1,200-baud modems.

That’s 1,200 bits per second. A modern 4G connection is about 10,000 times faster. Yet by the early 1970s, PLATO had hundreds of terminals across the U.S., all linked by telephone lines. It was the closest thing to a network before ARPANET opened to the public.

Empire: The First Game That Needed Another Human

Empire was built by John Daleske, a graduate student who wanted to simulate a real-time space battle. He wrote it in TUTOR, PLATO’s programming language. The game was simple: two players controlled spaceships on a grid, firing torpedoes at each other. But the twist was that you were playing against another person, not a computer AI.

This was radical. Video games before Empire were single-player: Pong (1972) let two people play on the same screen, but that was just a physical connection through the same machine. Empire was the first time two people, sitting in different rooms, perhaps hundreds of miles apart, interacted in real time through a computer network. They didn’t see each other’s face—they just saw dots move on a glow-orange plasma screen.

The Technical Sorcery: Making It Work Over Phone Lines

How did Daleske pull this off? PLATO was a time-sharing system. A central mainframe at the University of Illinois processed chunks of data from each terminal in rapid sequence. Daleske’s code updated the game state on the server every 1/30th of a second. Each terminal sent its player’s keypresses over the modem—phone lines that crackled with static, often dropping bits.

To keep the game playable, Daleske implemented a clever trick: both players’ screens were driven by the same program, but the server only sent “deltas”—tiny updates about where a torpedo moved or if a ship exploded. The local terminal handled the rest. This is the same concept used by modern multiplayer games like Call of Duty, where your client simulates the world while the server corrects it.

But there was a problem: lag. Phone lines in 1973 had latency as high as 500 milliseconds. Daleske compensated by making the game turn-based in a weird way. Each command took effect on the next server tick, so both players effectively had “time to react” built into the system. It was crude, but it worked.

The Wild West of Early Multiplayer

Empire wasn’t alone. PLATO soon hosted other groundbreaking online games: Maze War (1974), a first-person shooter, and Avatar (1979), an early dungeon-crawler that let 50 players share the same virtual world. Players dialed into the PLATO network from terminals in libraries and dorm rooms, often running up huge phone bills. In some cases, students would stay logged in for days to keep their in-game progress—because the server didn’t save your state when you disconnected.

The real revelation was social. Players formed clans. They left messages for each other. They even had online arguments. Empire had a command to type “HELLO” to the other player, and the first thing two strangers did was say hi. That moment—two humans connecting over a distance via a phone line—is the birth of everything from World of Warcraft to Discord.

Why This History Matters

Most people think the first online multiplayer game was Doom (1993) or Quake (1996). They’re wrong. The technology existed two decades earlier, hidden inside an educational mainframe. Empire’s legacy isn’t just a game—it’s the proof that the desire to play together is older than the internet itself. The phone lines that carried those 1,200-baud packets were the same copper wires that carried voices, but on them, they carried the first cries of digital togetherness.

If you’ve ever synced up with a friend to play Minecraft or found yourself shouting “He’s behind you!” on a headset, you owe a debt to a 1970s grad student who saw a plasma screen and thought, “What if two people could play on it…at the same time, but far apart?” That’s the untold history: a game that worked not because of wires, but despite them.