Prior to joining Infocom, Moriarty was a Technical Editor for the Atari 8-bit computer magazine ANALOG Computing. He wrote two text adventures for ANALOG: Adventure in the 5th Dimension (1983) and Crash Dive! (1984). He also worked on Tachyon (1985), an adaptation of Atari's Quantum arcade game, which was previewed but never published.
His first graphic adventure game was Loom, published in 1990 by Lucasfilm Games. After that, he worked on two sequels, Forge and The Fold, which were never released. The next adventure game he made was The Dig (1994), a game based on an idea from Steven Spielberg.
On occasion, Moriarty delivers public lectures, one of which has been turned into an amateur dramatic production.
^Cooke, Amy (24 May 2011). "Open Drama Night". Nouse: University of York's Student Website. Archived from the original on 3 June 2011. Retrieved 9 June 2011. A Brechtian style piece, based on a lecture Todd received by Brian Moriarty, the play explores the history or rather the historiography surrounding the issue of the authorship of Shakespeare’s plays.
^Moriarty, Brian (November 1986). "Designer Profiles / Brian Moriarty". Computer Gaming World. p. 16.|access-date= requires |url= (help)