Alfonso John Romero (born October 28, 1967) is a programmer and designer known for being a founding member of id Software. He was credited as a programmer at the time Wolfenstein 3D and Spear of Destiny were developed, being responsible for many gameplay design decisions and maps.
Romero was also majorly responsible for id classics Doom, and Quake. Prior to id Romero worked at SoftDisk where he created Dangerous Dave, Rescue Rover, and other various titles, usually in cooperation with id co-founder John Carmack. Games like Dangerous Dave would ultimately act as prototypes for games like id's Commander Keen.
After Wolfenstein, Romero ultimately took over as the creative mind fueling id's titles following Tom Hall's ousting during early development of Doom. During this time Romero adopted a rock star like attitude which followed him through his career at id until his departure after Quake. He then founded Ion Storm Entertainment where he created Daikatana.
Romero is sometimes credited with having the idea to base a game on the 1981 Muse Software game Escape from Castle Wolfenstein.