Where it starts: three little brown books in a woodgrain box, built on the Chainmail miniature rules. Supplements Greyhawk and Blackmoor follow in 1975–76 and quietly add much of what later editions treat as core — thieves, paladins, and the first settings in embryo.

The Basic fork opens: Dr. J. Eric Holmes edits a single introductory box meant to feed players into AD&D. One box, levels 1–3, and for many players the actual front door to the hobby.

Product list pending: this band gets its scaffold pass (Wikipedia as starting scaffold, verified against publisher sources before it ships) in a later phase.

The hardcover era: Monster Manual (1977), Player's Handbook (1978), Dungeon Master Guide (1979). TSR's flagship line for a decade — Greyhawk, the first Forgotten Realms box, Dragonlance, and the great module series (G, D, Q, S, T) all live here.

Tom Moldvay's Basic and David Cook's Expert sets rewrite the fork as a clean ladder of its own — the red box millions started with, and the Isle of Dread.

Product list pending: this band gets its scaffold pass (Wikipedia as starting scaffold, verified against publisher sources before it ships) in a later phase.

Frank Mentzer expands B/X into five boxes — Basic, Expert, Companion, Master, Immortals — a complete parallel game running beside AD&D until the fork closes in the 1990s with the Rules Cyclopedia.

Product list pending: this band gets its scaffold pass (Wikipedia as starting scaffold, verified against publisher sources before it ships) in a later phase.

A cleaned-up, reorganised AD&D — and the great setting explosion: Planescape, Dark Sun, Ravenloft's line, Birthright, and the Player's Option books late in the run. The catalog here runs to 2000, the line's last TSR/WotC transition year.

Wizards of the Coast rebuilds the game on the d20 System — and opens it with the OGL (see the SRD section). One core mechanic for nearly everything; the third-party flood follows.

The mid-edition revision becomes an era of its own: a deep bench of supplements, the Complete and Races series, and Eberron's debut.

A tactical, power-based redesign — and the Essentials line (2010–12) as its softer second act. The GSL replaces the OGL, and much of the open-game world moves to Pathfinder instead.

The best-selling edition: a leaner core, a decade of adventures and settings — and in January 2023, the OGL controversy that ends with the SRD placed in Creative Commons. One quirk of this era: Wizards of the Coast sells no official PDFs of the 5e hardcovers, so the digital links on these rows are the official Roll20 virtual-tabletop editions — and two books, Volo's Guide to Monsters and Mordenkainen's Tome of Foes, were withdrawn from Roll20 in 2022 and survive digitally only on D&D Beyond.