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Tim Sweeney

From ZZT to Unreal

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Tim Sweeney wrote ZZT in 1991 as a University of Maryland engineering student, sold it as shareware under the name Potomac Computer Systems, and turned the business into Epic MegaGames. He wrote most of Unreal's engine himself, licensed it to other studios, and still runs Epic Games, the maker of Fortnite, which has fought Apple and Google in court over their app stores.

In 1991 Tim Sweeney was a mechanical engineering student at the University of Maryland who studied by day and programmed by night. The program was ZZT, a text-mode adventure that came with its own editor, and he sold it by post under the name Potomac Computer Systems. Six years later Edge previewed his third game, Unreal, and reported that its engine was “incredibly, mostly the work of one programmer, Epic’s Tim Sweeney”. The company he had started to sell ZZT is now Epic Games, and he still runs it.

Fast facts

  • Born: 1970, and grew up in Maryland.
  • Company: founded as Potomac Computer Systems in 1991; Epic MegaGames by January 1993; Epic Games from 1999.
  • Games he wrote: ZZT (1991), Jill of the Jungle, and the engine of Unreal (1998).
  • Technology: the Unreal Engine, licensed to other studios from the late 1990s.
  • Honours: Academy of Interactive Arts & Sciences Hall of Fame (2012); Game Developers Choice Lifetime Achievement Award (2017).

ZZT, written at night

Sweeney learned on an Apple II. By his own count he wrote “maybe several hundred programs for the Apple, including maybe fifty little games”, and released none of them. At university he lived in a dormitory but kept his computer at his parents’ home in Maryland and did most of his work there. “I basically studied and did school work all day, then programmed all night – working on ZZT,” he told Benj Edwards in 2009. “On the weekends, I’d come home, and I had this little shareware business I was growing after I released the game.”

ZZT came out in 1991. Computer Gaming World found it “truly charming” and listed it at $14.95 from Potomac Computer Systems of Potomac, Maryland, a name Sweeney had picked when he planned to go into computer consulting. It sold three or four copies a day, and the registrations paid for his next game, Jill of the Jungle, a side-scrolling platform game. He renamed the company Epic MegaGames, “kind of a scam to make it look like we were a big company”, in his words. He never finished his degree: “Epic was growing rapidly, and I was one credit short after four years.”

By January 1993 Computer Gaming World’s shareware column was recommending two Epic MegaGames releases, Jill of the Jungle and Castle of the Winds. Sweeney wrote later that Jill “put Epic MegaGames on the map” and helped bring in other developers. Epic grew, he recalled, “from one person to about eight”, and most of the games that followed were other people’s: James Schmalz’s Epic Pinball, Cliff Bleszinski and Arjan Brussee’s Jazz Jackrabbit, and One Must Fall. The company sold them the way it had sold ZZT, giving away the first episode and selling the rest (see shareware).

Unreal

Sweeney went back to programming himself. Epic started Unreal, he recalled, in 1994. When Edge previewed it in January 1997 it ran at 25 frames a second on a 133MHz Pentium without a 3D card, with coloured lights, shadows and reflective water, and the magazine gave most of the credit to Sweeney. A month later it quoted him as lead programmer explaining why the game stayed first-person: “The main problem I have with, say, Mario 64 is that you get into these confusing bits where you wish the camera would go a certain way and it doesn’t.”

He had firm views on the hardware too. In May 1997 Computer Gaming World, introducing him as “chairman of Epic Megagames”, asked about Intel’s new MMX instructions. “I am actually surprised about the amount of fuss over this issue,” he said, “because MMX is a paradigm shift (scalar to SIMD programming) and developers should be exploring its new possibilities, rather than whining about it not supporting their favorite old programming tricks.”

Finishing the game took a change of scene. “We were well into the project, and we weren’t making the progress we needed because everybody was all over the place,” Sweeney said, “so we got everybody together in Waterloo, Canada for a year to finish the game.” Then the company chose a permanent home: “We looked all over the country, decided on Raleigh, and moved here in 1998.” Unreal came out that year, published by GT Interactive, and Edge gave it eight out of ten. By June 1999 Edge was reporting around ten games from other publishers built on its engine, and Epic, now Epic Games, was inviting licensees to “our offices in Raleigh, North Carolina”.

The engine

Sweeney stayed in charge of the technology as Epic grew. In 2004 he showed Edge Unreal Engine 3 with Mark Rein and Alan Willard, and named what he thought Epic did best: “we’ve always had a big focus on tools”. Its editor, he said, gave “a pixel-accurate rendering of what you see in the game. It’s a WYSIWYG editing environment, always has been.” The engine’s showcase was Gears of War (2006), and in 2012 Edge previewed the first game on its successor, Unreal Engine 4: Epic’s own Fortnite.

What changed most was how the engine was sold. In 2014 Epic began renting Unreal Engine 4 to anyone for $19 a month, with its full C++ source code on GitHub, and in March 2015 made it free to download, taking 5 per cent of a game’s gross revenue after the first $3,000 per product each quarter. Unreal Engine 5 followed in April 2022. In 2013 Sweeney told Edge that the industry was heading online, and that “you don’t need $100 million to build a triple-A game. But if you want to spend that much, you can build one that looks absolutely insane.”

Fortnite, the store and the courts

Fortnite reached players in 2017, and its free Battle Royale mode turned Epic’s own game into its biggest business: by 2020 Epic said it had more than 25 million daily players. In December 2018 Epic opened the Epic Games Store, taking 12 per cent of each sale against the 30 per cent usual elsewhere.

Sweeney then took the argument about store fees to court. In August 2020 Epic added its own payment option to Fortnite on the iPhone; Apple removed the game from its App Store and Epic sued. In September 2021 Judge Yvonne Gonzalez Rogers found for Apple on nine of Epic’s ten claims but ordered Apple to let developers tell players about other ways to pay. In April 2025 she found that Apple had “willfully” failed to comply, Fortnite returned to the American App Store in May 2025, and in June 2026 the US Supreme Court agreed to hear Apple’s appeal against the contempt finding. Epic’s parallel case against Google went to a jury, which found unanimously in December 2023 that Google held an illegal monopoly over Android app distribution and in-app billing.

The company has shrunk as well as grown. In September 2023 Sweeney announced that Epic was laying off 870 people, about 16 per cent of its staff, and in March 2026 it cut more than 1,000 jobs. It is now based in Cary, North Carolina.

Land conservation

Away from games, Sweeney has bought large areas of forest in North Carolina to protect them. In 2016 he paid $15 million for the 7,000-acre Box Creek Wilderness, in the foothills of the Blue Ridge Mountains, and gave a conservation easement over it to the US Fish and Wildlife Service, which keeps it from development.

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