As teenagers living in Lincoln, England in the 1970s, Richard Halliwell and his school friend Rick Priestley liked to play tabletop miniature wargames.
[5] During this time, he and Ansell collaborated on the rules for a science fiction wargame called Imperial Commander that featured a titanic struggle between two vast forces.
Once Halliwell was finished with the rules, Rick Priestley and Tony Ackland developed the product, and it was released by sister company Games Workshop in 1983 as Warhammer.
[16] After the 2020 rerelease of Block Mania and Mega-Mania, the UK print magazine Tabletop Gaming highlighted that "Richard Halliwell knew his source material well, ensuring it’s all thematically bang-on, and satisfying to die-hard Dredd fans.
[17] In 1988, Halliwell worked with Marc Gascoigne to design Dark Future, a Mad Max-like combat board game featuring a violent car race across North America.
[16][18][19] PCGamesN highlighted that "Dark Future drew on the marvellous design instincts of Richard Halliwell, then just a year away from publishing Space Hulk and introducing the word 'overwatch' to the sci-fi gaming lexicon".
[21] The following year, Halliwell collaborated with Matt Forbeck and Jervis Johnson to produce two Space Hulk expansions, Deathwing, and Genestealer.