Aaron Allston was hired by game designer and publisher Steve Jackson as circulation manager for Space Gamer magazine. Over the next two years, he became assistant editor and then editor of the magazine.

Aaron also began designing game supplements on a freelance basis for Steve Jackson Games and then for Hero Games. In 1983, shortly after Space Gamer won the H.G. Wells Award (a branch of the Origins Awards) for Best Role-Playing Magazine of 1982, he went freelance full-time as a game designer and editor, doing most of my work for Champions publisher Hero Games. He also began doing early development work for a Star Trek magazine, a project that did not pan out for him but gave him valuable insights into the licensed fiction industry. Three years later, he began doing work for Dungeons & Dragons publisher TSR, Inc., a relationship that was to last until the mid-1990s.

In 1990, Aaron did story development, character scripting, and other writing work for The Savage Empire, a dinosaurs-and-cavemen-with-magic computer game in the Worlds of Ultima line for Origin Systems, Inc. Subsequently he worked on several more computer game projects for Origins, gradually moving out of the field as he also transitioned away from paper role-playing game work.

Aaron's first novel, Web of Danger, game-based fiction supporting the Top Secret/S.I. game line, was released by TSR in 1988. Baen Books published his second novel (and first original fantasy), Galatea in 2-D. Subsequently he wrote and sold an average of a little over one novel a year, and gradually moved from game design to full-time fiction writing. In 1997, Aaron began working with the Star Wars Expanded Universe line; his first novel for the line, X-Wing: Wraith Squadron was released in 1998. Since then, more Star Wars novels, work for other licensed universes, and original SF&F have followed.