There are as many ways to divide up categories and styles of Dungeons and Dragons as there are editions of the game. The simpliest way does that, with:
- OD&D (White Box, or Original Dungeons and Dragons)
- BD&D (Basic, including Mentzer, Moldvay/Cook, BECMI, and the Rules Cyclopedia)
- AD&D (both First and Second editions; whether this covers things like Skills and Powers, and Unearthed Arcane is up to the reader)
- 3.X (I’d say this includes Pathfinder, as well)
- 4E (and Essentials.)
On some days I also divide things into Arcade, Gold Box, and Infinity, depending on what style I’m looking for through a video game lens. And I know there’s other D&D game series out there, but this is what makes sense to me. High action, tactical, more story driven.
But recently I’ve been using just two (!) categories for all 45+ years of D&D. There’s the 20th Century versions, up through 3rd Edtion in 1999* and 21st Century D&D, which includes 4E and 5E, which are diametrically opposed, depending on which internet forum you frequent. 20th Century D&D I find all bleeds together, even the grandaddy of the whole lot. It all starts out simple enough, and then gets weighed down by new features, additional rules, attempts at more realism or at least verisimilitude. It all shifts quickly, in each edition, from what works at the table to what makes sense as a world. These are good things! In moderation, at least - I’m beyond chasing down feats in 40 different books, but I did enjoy it for a time, and there’s people who still enjoy it.
21st Century D&D has a different feeling, even 5E, the “retro/throwback” edition. There’s more focus on what works at the table. There’s inclusion of modern game design. I’ve found both to be far friendlier to DM than any other edition (I haven’t ran Basic, to be fair), in the number of tools given to be used at the table. Or at speed, not slowing the game down. These are the lazy DM, low-prep games. Now, like most broad categories, if you stare at this one enough it starts to fall apart. For me, though, this is a helpful distinction.
- I include Pathfinder as a 20th Century game, as well. Pathfinder 2E might be a different critter entirely, but there’s such a straight line of RPG design theory and playstyle from 1999’s 3E launch and the last days of Pathfinder 1E that it’s no contest.