Original Dungeons & Dragons
Original EditionCore Mechanic
Ability scores are rolled on 3d6, and combat uses a d20 attack matrix keyed to class or Hit Dice and Armor Class. Initiative uses dice, saving throws use class-and-level tables, and spellcasters have limited spells remembered per adventure.
Best For
Groups who want an early fantasy campaign game with dungeon expeditions, open wilderness play, and substantial referee adjudication. It fits tables willing to choose or adapt procedures when the rules leave room.
Highlights
A class-and-level attack matrix turns a d20 roll into a direct Armor Class result. Separate dungeon, wilderness, aerial, and naval procedures let a campaign expand beyond expeditions. Referee-facing dungeon design and stronghold rules support an open campaign beyond a prepared scenario.
Considerations
Classes, race limits, spell lists, and attack matrices impose a specific early D&D structure. The original rules distribute important procedures across separate subjects rather than one universal task rule. Running strict 1974 requires separating the original rules from Chainmail references and later compilation material.