The post is primarily a quote, so I won’t repost the whole thing here. Instead, here’s the business end, an excerpt of the excerpt:
As my old friend, Dave Arneson, and I agreed, one simple die roll is all that one needs: failure or success. […] A low score on a D100 roll denotes success; a high score signifies failure. A middling score results in no effect, or an event that is inconclusive.
This quote comes from a Runequest-Con program book, long out of print. (Chris teased a follow-up, which appeared the next day; it’s also quite interesting: Empire of the Petal Throne, the “Gamist” Early Years.)
All you need is love (and percentile dice)
But I just want to zoom in on M.A.R. Barker’s system from the quote above — a system apparently also enjoyed, at least in a broadly similar form, by Dave Arneson. A system lighter than just about anything short of pure let’s-pretend — for crying out loud, it’s lighter than Risus (which I love), and Risus fits on a single sheet of paper.
What’s there is one die roll, and rough metric for success and failure. There’s no implied character differentiation, although another sentence or two could easily bake that in. There are no rules for doing specific things, and no real assumptions baked into the mechanics — other than that success or failure actually matter.
Because there is a die roll, and M.A.R. Barker also notes that “The players don’t really care, as long as the roll is honest.” A simple roll with a meaningful outcome is a super-distilled, narrative approach, and a fascinating one.
For years I’ve held that story games and old-school games have more in common than not. “Make one die roll, and then figure out what happens narratively” could just as easily describe the core mechanic of an indie RPG — and hey, in the mid-1970s, they were all indie RPGs.
I’ve played a small number of games with nearly this little in the way of mechanics, but I can’t recall ever playing one that combined such a simple system with old-school fantasy gaming. It sounds like a fun combination.
 Do you want inceptions? Because excerpting an excerpt is how you get inceptions.