industry report by the creators of Roll20 shows that the Basic Fantasy Role-Playing Game is a legitimately popular RPG, sitting between Pelgrane Press's 13th Age and Monte Cook's Cypher System in popularity. I've written in positive terms about BFRPG before, and I think it's a solid old school system. I still love its declaration of "This is OLD SCHOOL" even if I'd prefer a layout with a bit more pizazz. But BFRPG is smart in ways that other RPGs haven't thought about.
If you read the Project News page on the Basic Fantasy site, you will see that the game is constantly undergoing a process of being honed, re-proofed, corrected, and occasionally updated in very minor ways. It reads like a log of updates to a piece of software, right down to the release numbers and the idea of "release candidates" for print versions.
Basic Fantasy is, to my knowledge, the only RPG out there that is actually serious about the idea of being an open source RPG. You can literally download the Open Office document files that the rulebook PDFs (and the printed versions) are derived from, work on them, and if you want - make them your own. Swords & Wizardry has a single RTF document, but it's not the actual source of the layout for the print versions. Of course, this constrains the layout (see above), but it's a radically open concept in gaming.
The community recently leveraged this to create a Field Guide, a bestiary full of creatures both new and old. If you look at the amount of material between new classes, races, and additional/alternate rules, it's clear that there is a possibility for BFRPG to release a fairly thorough "Advanced" or "Companion" type of product with the ability to branch far beyond its four races and four classes. And since the rules are all modular, you can plug any of them into a game. And it doesn't even have to be BFRPG; it could just as well be Moldvay or Labyrinth Lord or LotFP.
But I don't think the open source approach is the only reason for Basic Fantasy's spread on Roll20, which I suspect may reflect broader support than many people realize. Because Basic Fantasy RPG is able to spread through Amazon. When I pull up FATE Accelerated, I see this on the third page of the related items scroller:
The Basic Fantasy rulebook pops up all over the RPG recommendations on the Internet's largest store, and it's a complete RPG for only five bucks. It has 83 reviews and 73 of those give it five stars. When you look at it you also see a book of monsters and four adventure books, each of them under $4. BFRPG, the Field Guide, Adventure Anthology 1, BF1 Morgansfort, BF2 Fortress Tower and Tomb, and JN1 The Chaotic Caves combined cost only $23.96, and easily provide a weekly group with a year's worth of adventure. At $5, extra copies of the rulebook for the table are not an expensive luxury; each player could have the rulebook, even though they don't really need it.
I suspect that BFRPG has been quietly spreading old school gaming ideas through its placement on Amazon. And that's all to the good. Not everything in the OSR is loud and shiny and front and center; a lot of people are just playing straighforward RPGs that make a good time for them and their friends. Which is kind of humbling from the perspective of those of us toward the center of OSR circles.
Basic Fantasy has been continuously revised and updated, even if only incrementally, for almost a decade. It's a quality open source product and its community is doing as much as any publisher out there to build old school roleplaying. It is what it says on the box: a meat and potatoes old school experience. And it deserves more acclaim than I think it gets.