When new RuneQuest line editor Ken Rolston kicked off the so-called "RuneQuest Renaissance" for Avalon Hill, his first publication was O'Brien's (1992).:179 O'Brien contributed to later RuneQuest releases in the product line during Rolston's tenure at Avalon Hill.
O'Brien published two issues of another fanzine, the Glorantha Con Down Under fundraiser Questlines (1995-1998).:360 These were published in 1995 and 1998 as fund-raisers for gaming conventions held in Melbourne, Australia. O'Brien also created #1 (Summer, 2000) a fake fanzine that purported to be a rare collectible from 1982.:360 This magazine was produced for a British gaming convention in 2000, and because it nevertheless featured original material by Ken Rolston, Greg Stafford, David Hall and O'Brien, Gorp is considered valuable and collectable in its own right.
In 2015 O'Brien became a co-owner of Moon Design Publications, along with Rick Meints, Jeff Richard and . Later that year as part of an announcement by Greg Stafford that Moon Design Publications had joined the ownership group of his iconic game company Chaosium, O'Brien became vice president of Chaosium.
- Shannon Appelcline (2011). Designers & Dragons. Mongoose Publishing. ISBN 978-1-907702- 58-7.