This morning (that being the morning I’m writing this, not the morning of its scheduled posting), I was scrolling through the Pathfinder 2e subreddit over breakfast and ran across a post asking why readers prefer PF2 over rules-light systems. Several someones made the point which I would have made if I were going to comment: that different game systems are different tools for achieving different storytelling experiences and outcomes.

The comment thread that prompted this post, however, was this one, in which the OP expressed surprise that someone could be capable of running more than one game system without getting rules crossed up.

I had a bit of an “oh, sweet summer child” reaction to that. It never had occurred to me that this might be a problem. I’ve been collecting accumulating TTRPGs since my childhood in the early ’80s and studying and running them semi-regularly since the early ’90s. Each one still occupies a measurable amount of my brain. While I can’t claim to be able to run anything 100% off-book, the RPGs for which I could play or run tomorrow without much fumbling, unfamiliarity, or pre-session review are, off the top of my head:

• 7th Sea (original)
• Dungeons & Dragons (5e, 3e as a stretch)
• Feng Shui (either edition)
• Legend of the Five Rings (original through 4th)
• Shadowrun (2e and 3e)
• Spycraft (original and 2.0, including Stargate SG-1 as an intermediate member of that line)
• Trinity (original)
• Twilight: 2000 (v2.2 and v4)
• Vampire: The Masquerade (original through Revised and 20th Anniversary)

At one time or another, I’ve spent enough time at the table for each of these to develop a decent familiarity with the mechanics. I can make a spontaneous rules call at the table and be fairly confident that my off-the-cuff decision will be consistent with the game as written. Of equal importance, I also know each of the settings (or genre assumptions, in the case of setting-less games like Spycraft) well enough to improvise plot and the world’s responses to the PCs’ actions.

In a pinch, I also could do passably-good GM work with the rest of the original World of Darkness (strongest in Wraith: The Oblivion, weakest in Changeling: The Dreaming), Dark Conspiracy, Earthdawn, Star Wars (WEG or FFG), and a good cross-section of the Powered by the Apocalypse family.