John A. Theisen
John A. Theisen  was a role playing game designer and writer for FASA and GDW from the mid-1980s through the early 1990s. He worked on Star Trek and Mechwarrior for FASA and Space: 1889 for GDW. In addition, he wrote a number of articles for various gaming magazines. He was credited with writing and design on eight supplements in the Star Trek line, and "timeline assistance" on one other, "The Federation". He also taught Star Trek briefly at the New Mexico State University Carlsbad.

He currently lives in Phoenix, Arizona and works there for a government agency, where he is involved in research, statistics, policy and contract compliance, trend analysis, and emergency preparedness.

Star Trek game authors