I don't say that with any kind of snark. I didn't have the money to order every book I wanted. So, I got the Red Box and the B/X rules fairly early and that was all I had for awhile. Somewhere along the way, I acquired Ghost of the Lion (B Solo adventure) and a few other things as well. It was years before a friend donated their 1e DMG, PHB and MM to me. I bought the Manual of the Planes at some point as well as my much beloved Spelljammer. I don't remember how I got Dragonlance. I vaguely remember buying the Companion rules from the BECMI set and I know I purchased the 1e Oriental rules and ran Sword of the Damiyo a couple times.
I don't have my entire collection anymore thanks to my stupid self leaving a bunch of stuff in a car that got towed. I miss my Oriental Adventures hardback as well as my World of Bian notebook that had everything in it.
I lived in a somewhat remote area of NC. There was no game store or large group of gamers that I knew. In fact, my high school group was one of three that I knew of within a 50 mile area. This didn't keep us from figuring out what we liked and making up stuff to keep the game going.
We started with the Red Box, I'm sure. So we got used to race as class and straightforward combat. After third level, we found a copy of the Moldvay's Expert Rules. They seems to fit okay despite the art not matching. In Moldvay, we found rules for all kinds of things like sea battles and aerial combat. More than that were lots of spells. The Dungeon Master section was a treasure trove of all kinds of things including the magical research tables, Roll under ability score for saving throws and creating your own dungeons/hexcrawls. We stopped looking for pre-made adventures and went for making our own.
As each new book came into our group, more possibilities arose. With 1e books, we found that race and class could be separate. There were all kinds of classes like Druids and Illusionists, as well as characters with Psionic powers. Of course with the DMG, we started making all kinds of things. For some reason, I loved intelligent weapons. I even made an intelligent whip.
Which edition were we playing? God only knows. Combat was Red Box. Character advancement was whichever book we got the class from. I played in a game with one of the other groups in town and I was disoriented by the straight 1e by the book combat and associated rules.
Early games were hack-n-slash, murderhobo, and/or munchkin. Kill things and take their stuff was about as much as we cared about. Later on, though, we became interested in finding really strange places. Once one of us got Greyhawk, we were immediately drawn to the Sea of Dust. We simply had to find the Forgotten city.
After covering areas on and off the Greyhawk map, the group was itching to visit the Outer Planes, so off we went. After I purchases Spelljammer, we were off to every sphere you can imagine. In some sense, the multiverse was never big enough for us and that was really fun.
By the time we were finished buying this hodgepodge of rules, combat was still Red Box with 1e Psionics and Grappling rules with Spelljammer's Aerial rules. Monsters were stated for 2e or B/X. We awarded XP for exploration and we had our own rules for it. Character advancement was still "whichever book its in", including the 1e Oriental Adventures book
Thanks to the OSR and dndclassics.com, I can make my own edition again, especially as I have lost many of my notes from later years and all of them from college. My current edition now is:
Swords & Wizardry Complete with S&W Core Classes only (plus my own). I have my own psionics rules as well as two alternate magic systems, in addition to the Vancian system. S&W Complete is used for combat, except for aerial, naval, and mecha combat, which uses Option 3. For Mass Combat, I use the Rules Cyclopedia War Machine rules. I use the ACKS system to build magic items and 1st level characters can research/make magic items. I award XP for money spent and exploration. For now, exploration is a flat amount based on location. I use the Saving Throw as a skill system. I use the OSRIC Specialist system for hirelings, mostly.
Oh yeah, the economy is entirely silver based and loosely based on the ACKS economic system.
One day, I'll write it all down. It's D&D Mine and I love it. By goodness I'll have a Spelljammer set of rules as well.