John Romero was a co-founder of id Software and the studio’s most visible designer and gameplay programmer. While John Carmack built the rendering engines, Romero built much of what players actually experienced: level layouts, game feel, and the tools that made rapid level construction possible. He designed levels and gameplay across the studio’s foundational titles, including Commander Keen, Wolfenstein 3D, Doom, and Quake, and is widely credited with coining the term deathmatch for competitive multiplayer combat.
Romero’s contributions are visible in id’s own released source code. The Doom source release at github.com/id-Software/DOOM, which he co-authored as part of the id team, embodies the data structures and level format that his editing tools produced. He wrote internal tools such as DoomEd and QuakeEd, the level editors that the rest of the team used to build maps, making him as much a toolsmith as a designer.
Romero maintains an active personal site at rome.ro, where he writes firsthand about his ongoing work in the Doom and Quake ecosystems. His 2019 episode SIGIL, a new chapter for the original Doom, is documented there in his own words, including technical detail about how every line segment in a Doom level carries data and how he tuned individual encounters based on playtesting. The site stands as a primary record of his continued hands-on involvement with the engines he helped popularize decades earlier.
His design philosophy emphasized pacing, surprise, and player agency within the constraints of id’s fast engines. The first episode of Doom, much of which he designed, became a template for first-person shooter level design: interconnected spaces, secrets, escalating threat, and a strong sense of place built from a small palette of textures and enemies.
After leaving id in 1996, Romero co-founded Ion Storm and later Romero Games, but his place in programming history rests on the early id era, when his collaboration with Carmack turned a small Texas studio into the definers of an entire genre. The pairing of Carmack’s engine work and Romero’s design and tooling is one of the clearest examples in software history of complementary technical talents producing something neither could have built alone.