How one programmer built a theme park in machine code
Chris Sawyer wrote RollerCoaster Tycoon almost entirely in x86 assembly language, the instruction set a processor runs directly, at a point when nearly every commercial PC game was written in C or C++. His own FAQ at Chris Sawyer Software Development gives the split exactly: the game is "99% written in x86 assembler/machine code, with a small amount of C code used to interface to MS Windows and DirectX."
Assembly trades readability for control. A routine that takes ten lines of C can take fifty or a hundred lines of assembly, and the programmer allocates registers and memory by hand. Sawyer had been writing it since the 1980s and carried years of his own tested routines forward from project to project, so the slow language was, for him, the fast one.
The payoff showed on screen. The game tracked hundreds of individual guests, each with hunger, thirst, happiness and its own pathfinding, while running ride physics and scrolling a detailed isometric park on a consumer Pentium. Sawyer did not do everything: Simon Foster drew the graphics and Allister Brimble composed the music.
How well did RollerCoaster Tycoon actually sell?
Hasbro Interactive released the game in North America on March 22, 1999 under the MicroProse label, the same label that had published Sawyer's Transport Tycoon in 1994. There was no large marketing campaign behind it.
It sold anyway. RollerCoaster Tycoon moved more than 700,000 copies in the United States during 1999 and took about $19.6 million in revenue that year. By July 2002 it had passed four million copies sold. Sawyer posted on his own website in January 2000 that it had finished 1999 as the top-selling PC game of the year.
The money behind those numbers only became public when the franchise ended up in court. Reporting on Sawyer's 2005 claim against Atari put the series' total revenue at roughly $180 million, of which about $30 million had already gone to Sawyer in royalties. For a title with one programmer, one artist and one composer, that is an extraordinary split. The Sims, the PC game that eventually overtook it, was built by a full Maxis team.
Why Chris Sawyer took Atari to court
Sawyer commissioned a forensic audit of his royalties in 2003. It concluded he was owed $4.8 million more than he had been paid, and in 2005 he sued Atari in the United Kingdom. Engadget reported the claim on November 8, 2005.
Atari counter-claimed in 2006, arguing it had in fact overpaid Sawyer by $1.6 million. That claim was dismissed in 2007. The two sides settled out of court in 2008 and the terms were never published.
The case matters for a reason beyond the money. Sawyer never sold the property. The rights to the games he designed stayed with him personally, which is why every RollerCoaster Tycoon release since has been somebody else publishing his trademark rather than owning it.
What went wrong with the games made without Sawyer
Sawyer wrote RollerCoaster Tycoon 2 himself, again in assembly, and Infogrames published it in North America on October 15, 2002. For the third game he stepped back to a consulting role. Frontier Developments built RollerCoaster Tycoon 3 in full 3D and Atari published it on November 2, 2004. It was a real technical leap, and it was the last entry the series' creator had any hand in.
What followed was worse. RollerCoaster Tycoon 4 Mobile arrived in April 2014 as a free-to-play build full of in-app purchases, made without Sawyer. It holds a Metacritic score of 35 from 13 critic reviews. Chris Schilling of Eurogamer scored it 1 out of 10 in 2014 and called its music "irredeemably bad".
RollerCoaster Tycoon World, developed by Nvizzio Creations and published by Atari on November 16, 2016, went the same way: about 26% of its roughly 1,980 Steam user reviews are positive. Frontier Developments released Planet Coaster the same year, and for most players that was the sequel the series never officially got.
Is RollerCoaster Tycoon still being made in 2026?
Yes, and 2026 is the franchise's busiest year in a decade. Atari and the studio Springloaded announced RollerCoaster Tycoon Wonderworks at gamescom Opening Night Live on August 25, 2026. It enters Steam early access in winter 2026 at $24.99, with console versions planned after the full release. Wade Rosen, chairman and chief executive of Atari, said in the announcement: "RollerCoaster Tycoon is a franchise that has deep meaning to fans, many of whom have played these games for a decade or more."
Ownership sits in two pieces. Chris Sawyer holds the RollerCoaster Tycoon trademark and the rights to the games he designed, and Atari publishes the series under what it describes as a long-term licensing agreement with him. Atari bought the publishing rights to RollerCoaster Tycoon 3 from Frontier Developments on April 2, 2024 for up to $7 million, $4 million up front and $3 million deferred, in a deal covering eight titles in the series. In November 2024 Sawyer sold Atari the Transport Tycoon intellectual property outright.
The back catalogue keeps moving as well. RollerCoaster Tycoon Classic, the rebuild of the first two games, reached Nintendo Switch 2, PlayStation 4 and Xbox One in May 2026, after launching on PC in September 2017 and on Nintendo Switch in December 2024.
How to play the original RollerCoaster Tycoon today
Three routes work in 2026. RollerCoaster Tycoon Classic is the maintained version, a rebuild of the first two games that carries the RollerCoaster Tycoon 2 expansion packs; it lists at $19.99 on Steam and runs on current consoles. RollerCoaster Tycoon Deluxe and the RollerCoaster Tycoon 2: Triple Thrill Pack are the original 1999 and 2002 builds, repackaged to install on modern Windows, and they are the cheapest way in when the series goes on sale.
The third route is OpenRCT2, a free open-source re-implementation of RollerCoaster Tycoon 2 that adds higher resolutions, multiplayer and modern window handling. It is not a standalone game. It needs the data files from a copy of RollerCoaster Tycoon 2 or RollerCoaster Tycoon Classic, so you buy the old game and run the new engine on top of it. For anyone who would rather run a 1999 disc as it shipped, the same methods that run 90s PC games on Windows 11 apply here too.
Where to find one today: the digital versions are the sensible option, because the 1999 CD-ROM needs a working optical drive and a patch before it will start. RollerCoaster Tycoon Deluxe and the Triple Thrill Pack are sold DRM-free and both fall to a few dollars in seasonal sales. Browse the RollerCoaster Tycoon listings on GOG.
Frequently Asked Questions
Who owns RollerCoaster Tycoon now?
Chris Sawyer still owns the RollerCoaster Tycoon trademark and the rights to the games he designed. Atari publishes the series under a long-term licensing agreement with him, and bought the publishing rights to RollerCoaster Tycoon 3 from Frontier Developments in April 2024 for up to $7 million.
Is there a new RollerCoaster Tycoon game in 2026?
Yes. RollerCoaster Tycoon Wonderworks, developed by Springloaded and published by Atari, was announced on August 25, 2026 and enters Steam early access in winter 2026 at $24.99. Console versions are planned after the full release.
Was RollerCoaster Tycoon really written in assembly language?
Yes. The FAQ on Chris Sawyer's own site says the 1999 RollerCoaster Tycoon is "99% written in x86 assembler/machine code, with a small amount of C code used to interface to MS Windows and DirectX." Simon Foster drew the graphics and Allister Brimble wrote the music.