While this magazine covered many science fiction games from various publishers, it began as the house journal of Game Designers Workshop. The first issue of Challenge was #25 as it continued the numbering from The Journal of the Traveller's Aid Society magazine it replaced. Challenge continued through to Issue 77, an issue 78 was planned but never published.
The Journal of the Traveller's Aid Society continued as a distinct section of the magazine, completed with it's own internal "cover", supporting classic Traveller until #36. After that, which coincided with the release of of MegaTraveller, Traveller articles were integrated with the rest of the magazine.