The original D&D was published as a box set in 1974 and featured only a handful of the elements for which the game is known today: just three character classes (fighting-man, magic-user, and cleric); four races (human, dwarf, elf, and hobbit); only a few monsters; only three alignments (lawful, neutral, and chaotic). With a production budget of only $2000 to print a thousand copies, the result was decidedly amateurish.

The rules assumed that players owned and played the miniatures wargame Chainmail and used its measurement and combat systems. An optional combat system was included within the rules that later developed into the sole combat system of later versions of the game. In addition, the rules presumed ownership of Outdoor Survival, a board game by then-unaffiliated company Avalon Hill for outdoor exploration and adventure. D&D was a radically new gaming concept at the time, and it was difficult for players without prior tabletop wargaming experience to grasp the vague rules. The release of the Greyhawk supplement removed the game’s dependency on the Chainmail rules, and made it much easier for new, non-wargaming players to grasp the concepts of play. It also inadvertently aided the growth of competing game publishers, since just about anyone who grasped the concepts behind the game could write smoother and easier to use rules systems and sell them to the growing D&D fanbase (Tunnels & Trolls being the first such).

Supplements such as Greyhawk, Blackmoor, Eldritch Wizardry and Gods, Demi-Gods & Heroes, published over the next two years, greatly expanded the rules, character classes, monsters and spells. For example, the original Greyhawk supplement introduced the thief class, and weapon damage varying by weapon (as opposed to character class). In addition, many additions and options were published in the magazines The Strategic Review and its successor, The Dragon.