A History of the World's Most Popular Roleplaying Game

April 4, 2026

The Beginning: Original D&D (1974)

In 1974, Gary Gygax and Dave Arneson published Dungeons & Dragons through Tactical Studies Rules (TSR). The game arrived as three digest-sized booklets — Men & Magic, Monsters & Treasure, and The Underworld & Wilderness Adventures — commonly referred to as the "three little brown books." It grew out of Chainmail, a miniature wargame Gygax had co-authored with Jeff Perren, but it introduced something wargames did not have: each player controlled a single character rather than an army, and a referee (the Dungeon Master) controlled the world.

The original game had three classes — Fighting Man, Magic-User, and Cleric. All hit dice were d6. All weapons dealt d6 damage. Armor Class was descending, starting at 9 for an unarmored character. The rules assumed familiarity with Chainmail and miniature wargaming conventions, and large portions of play were left to the Dungeon Master's judgment. The game was a framework as much as a ruleset.

Four supplements followed between 1975 and 1976. Greyhawk (Supplement I) introduced the thief class, variable hit dice by class, variable weapon damage, and percentile strength for fighters with a Strength score of 18 — changes significant enough that they became standard in nearly every subsequent version. Blackmoor (Supplement II) added the assassin and monk. Eldritch Wizardry (Supplement III) introduced psionics and the druid. Gods, Demi-Gods & Heroes (Supplement IV) provided mythological pantheons for use in play.

Holmes Basic (1977)

By 1977, Dungeons & Dragons had grown well beyond the wargaming audience it was written for. New players were picking up the game without any background in miniatures or wargaming conventions, and the original booklets were not easy to learn from. TSR commissioned J. Eric Holmes, a professor and D&D enthusiast, to edit and reorganize the rules into an introductory set covering levels 1 through 3.

The Holmes Basic Set was the first boxed D&D product and the first version designed to bring new players into the game. It streamlined the original rules, clarified procedures, and provided a more structured introduction to play. It was explicitly an entry point — the rulebook directed players to transition to Advanced Dungeons & Dragons for continued play beyond level 3. Its publication alongside the developing AD&D line created the first split between a "Basic" and an "Advanced" version of the game, a division that would persist for nearly two decades.

Advanced Dungeons & Dragons 1st Edition (1977–1979)

While Holmes was preparing the introductory set, Gygax was working on a far more ambitious project: a comprehensive, authoritative codification of the game. Advanced Dungeons & Dragons was published across three hardcover volumes — the Monster Manual (1977), the Players Handbook (1978), and the Dungeon Masters Guide (1979). Together, they expanded every aspect of the game.

AD&D introduced new classes (paladin, ranger, illusionist, assassin, monk, druid, bard), new races (half-elf, gnome, half-orc), and a dense web of subsystems. Fighters rolled d10 for hit dice. Characters with 18 Strength rolled percentile dice for additional bonuses — a mechanic originating in the Greyhawk supplement and unique to the Fighter class. Weapons had speed factors and dealt different damage against differently sized opponents. Saving throws split into five categories. Combat used matrices cross-referencing class, level, and Armor Class. The Dungeon Masters Guide alone ran over 230 pages, covering everything from random dungeon generation to the economics of gem trading.

AD&D became the dominant version of the game through the late 1970s and 1980s. It was the edition that brought D&D into the mainstream, for better and worse — the game's growing cultural visibility also made it a target during the "Satanic Panic" of the early 1980s, a period of moral concern over the game's content that led to significant public controversy but did little to slow its growth.

B/X: Moldvay/Cook (1981)

In 1981, TSR released a revised Basic Set edited by Tom Moldvay, paired with a new Expert Set edited by David "Zeb" Cook with Steve Marsh. Together, these two booklets — commonly called "B/X" — covered character levels 1 through 14 and provided a complete, self-contained game. B/X was not a simplified version of AD&D. It was a separate game line with its own rules, its own assumptions, and its own identity.

B/X used race-as-class: elf, dwarf, and halfling were classes in their own right, not races that could be combined with a class. Hit dice varied by class (d8 for fighters, d4 for magic-users). Weapons dealt variable damage by type. The rules were concise, well-organized, and complete. Procedures for dungeon exploration, wilderness travel, and encounter resolution were laid out clearly and systematically. B/X is widely regarded as the best-organized edition of classic D&D, and its clarity has made it the most common foundation for modern retroclones.

BECMI and the Rules Cyclopedia (1983–1991)

Beginning in 1983, Frank Mentzer rewrote the Basic D&D line as a series of five boxed sets: Basic (levels 1–3), Expert (levels 4–14), Companion (levels 15–25), Master (levels 26–36), and Immortals (beyond level 36, where characters ascended to godhood). This progression — known as BECMI — was the most expansive version of the Basic line, extending play far beyond what B/X or AD&D had formally supported.

In 1991, Aaron Allston compiled and edited the BECMI rules into a single hardcover volume: the Rules Cyclopedia. It covered levels 1 through 36, including the Companion and Master tier rules that had previously been available only in their respective boxed sets. The Immortals rules were excluded. The Rules Cyclopedia was the last major product in the Basic D&D line and remains the most complete single-volume presentation of that branch of the game.

AD&D 2nd Edition (1989)

In 1989, TSR published Advanced Dungeons & Dragons 2nd Edition, designed by David "Zeb" Cook. The new edition revised and reorganized the 1st Edition rules. Some subsystems were streamlined or removed — percentile strength was retained, but the assassin and monk classes were dropped, and half-orcs were removed as a player race. The non-weapon proficiency system, which had appeared as an option in 1st Edition's Dungeoneer's Survival Guide and Wilderness Survival Guide, became a standard part of the game. THAC0 (To Hit Armor Class 0) replaced the combat matrices as the primary method for resolving attacks.

The 2nd Edition era saw an expansion of campaign settings. Forgotten Realms and Dragonlance had been established in the late 1e period, but 2e added Dark Sun, Planescape, Spelljammer, Ravenloft, Birthright, Al-Qadim, and others. TSR published aggressively through the early and mid 1990s, releasing a large volume of settings, supplements, novels, and boxed sets. This period represented the company's commercial peak, but the pace of production eventually outstripped demand.

TSR's Fall and the Wizards of the Coast Acquisition (1997)

By the mid-1990s, TSR was in serious financial trouble. Years of overproduction had left warehouses full of unsold inventory. The company owed significant debts to its distributor, Random House. Internal management problems compounded the situation. In 1997, Wizards of the Coast — the company behind Magic: The Gathering, the collectible card game that had reshaped the hobby gaming industry — acquired TSR and with it the Dungeons & Dragons brand. It was the first time D&D had changed ownership since its creation.

D&D 3rd Edition and the Open Game License (2000)

In 2000, Wizards of the Coast released Dungeons & Dragons 3rd Edition, designed by Jonathan Tweet, Monte Cook, and Skip Williams. The new edition rebuilt the game from the ground up around a unified mechanic: roll a d20, add modifiers, meet or beat a target number. Armor Class became ascending. Attack rolls, saving throws, skill checks, and ability checks all used the same core resolution. The game introduced feats (selectable abilities gained at intervals), skills as a unified system, and prestige classes (specialized classes entered through in-game prerequisites).

Alongside the game itself, Wizards of the Coast published the Open Game License (OGL). The OGL was a legal framework that divided game content into two categories: Open Game Content and Product Identity. Open Game Content — the mechanical rules, stat blocks, and game systems — could be freely used, modified, and republished by anyone who accepted the license terms. Product Identity — setting-specific names, characters, and lore — remained proprietary.

The OGL was designed to encourage a third-party publishing ecosystem around the d20 System, and it succeeded in that goal. But it also had a consequence that extended well beyond 3rd Edition: because the mechanical rules of D&D were now Open Game Content, it became legally permissible to restate the rules of older editions. The game mechanics of Original D&D, Basic/Expert, and AD&D were not copyrightable in themselves — game mechanics generally are not — but the OGL provided a clear, tested legal framework for doing so. A revised 3.5 Edition followed in 2003, refining and rebalancing the system.

The Retroclones

In the years following the OGL's release, a number of publishers used it to create games that restated the rules of earlier D&D editions. These games — commonly called retroclones — were not reprints or copies of the original books. They were new publications that reproduced the underlying game mechanics in original text, making it possible to write and sell new adventures, supplements, and tools compatible with out-of-print editions of D&D.

The major retroclones and the editions they restate:

These games exist because specific versions of D&D went out of print, and the people who wanted to keep playing them also wanted new material. The OGL made it legal to publish that material.

Attribution & Legal Notice: This post references the following publications. All trademarks and Product Identity remain property of their respective owners.

Game mechanics referenced in this post are Open Game Content used under the Open Game License v1.0a where applicable. This post is a historical overview and does not reproduce game rules.