[7]: 191  When West End Games declared bankruptcy in 1998, Costikyan and Goldberg tried to recover the rights to Paranoia; although West End's founder Scott Palter tried to fight this, a judge gave the rights back to the creators in 2000.

[7]: 306–307  Costikyan and Goldberg licensed Paranoia to Mongoose Publishing, which began producing new books for the game in 2004.

[8] In May 2011, he joined Disney Playdom as senior games designer and in January 2014 assumed the same role at Loop Drop.

In June 2015, Costikyan joined Boss Fight Entertainment as senior games designer.

[10] As of 2019, Costikyan and Goldberg both joined Playable Worlds, a gaming startup founded by Raph Koster focused on producing the MMORPG, Stars Reach.

Costikyan worked on game design for many years, including writing and consulting for Nokia.

His novel One Quest, Hold the Dragons includes several stories about crottled greeps, a Slobbovian meme.

[22] In February 2009, Costikyan updated the rules and re-released his 1979 space combat game, Vector 3, under a Creative Commons license as a free PDF download.

By the Sword (1993, ISBN 0-312-85489-7) is another irreverent fantasy about a young barbarian who is forced by circumstances to make his way in the larger world; it was originally serialized on the Prodigy online service.

- 2000, ISBN 0-312-87396-4), depicts (with much dry humor) the vast sociological and economic changes that happen after aliens arrive on Earth, and one entrepreneur's efforts to survive and make a new start.