6. Thieves’ Guild (1984)
The cool thing about D&D is that people want to mess around with it, then when they do, they call it something else and people play it, tinker with it, and the cycle repeats. This desire to fix or customize D&D is the reason there is a larger RPG hobby and it established a DIY tradition that spans five decades (and has created a sense that the space is owned by the player community, rather than the publishers – one of my favorite things about RPGs at large).
Thieves’ Guild is a pretty typical example of this phenomenon, no better or worse than dozens of others. I love it though, because it recenters D&D around the Thief class, and Thieves are my favorite class (probably because Fritz Leiber’s stories about the rogues Fafhrd and the Gray Mouser are my favorite fantasy yarns). It accomplishes this realignment with deep detail on every sort of thieving activity you can imagine – banditry, kidnapping, the use of the grappling hook, the application of poison and so on. The line sustained Gamelords for four years, produced this box set, eleven supplements of rules and adventures, and a sub-line dedicated to detailing a fantasy world (particularly the city of Haven) where players could ply their nefarious trades. Gamelords eventually shuttered, but the Thieves’ Guild ideas, like all the many DIY projects over the decades, remain in the hobby’s collective DNA.