Brewing the Game Fantastic...

My favorite feature of gaming in the late 1970s (aside from the manual type and amateur aesthetic) was the rules-are-just-a guide mentality. We were playing D&D, a common tongue known by all, with each campaign a quaint regional dialect. From a thick Boston accent to lazy southern drawl, we spoke the same language, but it was different. The referee could mix and match what they wanted, even taking from other games. Decades later, our so-called classic catalog tries to do the same. You can eat 'em RAW or get creative...

RAW (rules-as-written) is fine; but you can add or change anything to suit your style, and guess what? Our stuff was deliberately made for this. Try these: 

Barons of Braunstein with Pits & Perils' armor system (and for added detail, assign bonus hits per Gaming Primitive). Oh, and maybe its magic items as rare artifacts...

Blood of Pangea using Barons of Braunstein's literacy system and/or Gaming Primitive's dual hit point/skill point approach for versatile heroes and gameplay...  

Diceless Dungeons, but with Barons of Braunstein's dicey combat and modifiers.

Pits & Perils, with Barons of Braunstein's mass combat and siege rules with outcomes tied to specific actions undertaken by the characters on some secret mission...

Each of these has its own feel; which is to say, Barons of Braunstein is experienced quite differently, thematically and mechanically, than say, Pits & Perils. But they snap together like Lego blocks with minimal effort. They have a shared core. It isn't quite an engine (I reject mechanical builds and video-game comparisons); but make your system simple enough and focus on content (monsters and the like), and you get something very much like an engine, although a common tongue with many regional dialects is my preferred comparison. 

Mentors: Gaming's Miyagi Effect...

Back in the 70s you couldn't learn D&D by reading the little brown books, much less the luxurious hardcovers, all of which were reference works for the already initiated. Long story short, you couldn't learn without a mentor. Or two or three. An indulgent group willing to instruct a neophyte (although let's be honest, we always wanted new players). In this way D&D was much like an apprenticeship, and gaming akin to magic*...

Until 1977, when Holmes Basic reached out to a generation of new gamers, condensing these mysteries into 48 classic pages. Its readers were subsequently directed to AD&D, and who wouldn't crave the upper levels of power those hardcovers represented? This was a necessary avenue for many, although personal instruction remained the principal gateway as these new DMs sought players (assuming most took up that essential vocation).

When the Basic Set (1981) landed, I assumed it was an updated tutorial. The Expert set cleared that up; but this parallel track still led many to AD&D. And once again, it spurred ever-increasing numbers to join the pastime and train their interested peers. Imagine an honest pyramid scheme where everyone wins. Anyway, for players learning the rules this way, there had to be at least one friend or family member ready to receive instruction.

A lot's happened since then. The parallel tracks converged; but every new edition has its introductory rules. Gaming's mainstream now, and you could probably learn how to play just about anything with a google search. But it's still in-person mentoring (allowing for online instruction with a human on the other end), that holds the hobby's attention, initiating fresh players into mysteries beyond any rulebook to bestow. Mr. Miyagi would be proud...

*Mine was a walk-in. My neighbors were playing with their garage door open!