There were four major editions of the "Basic" (i.e., non-Advanced) Dungeons & Dragons game:
First Edition (not to be confused with the Original Edition - see below)
1977 - Dungeons & Dragons Basic Set (First Edition) (blue box with red dragon)
1981 - Dungeons & Dragons Basic Set (Second Edition) (magenta box set with two adventurers battling a dragon)
1981 - Dungeons & Dragons Expert Set (light blue box with wizard scrying on the scene from the red box)
Third Edition ("BECMI")
1983 - Dungeons & Dragons Set 1: Basic Rules (red box with red dragon attacking hero with shield)
1983 - Dungeons & Dragons Set 2: Expert Rules (blue box with dragon attacking hero on horse)
1984 - Dungeons & Dragons Set 3: Companion Rules (aqua box with dragon attacking hero on mountain top)
1985 - Dungeons & Dragons Set 4: Master Rules (black box with hero riding a gold dragon)
1986 - Dungeons & Dragons Set 5: Immortals Rules (gold box with red dragon in background and powerful hero flying)
1991 - Dungeons & Dragons Game (New Simplified Version) (black or full-color box with dragon fight scene),
1991 - Dungeons & Dragons Rules Cyclopedia (containing cleaned up rules from Sets 1-4 above), and the follow-up Wrath of the Immortals
All rule sets, supplements, modules, variant rules, etc. that were written to support, or be used with, any of these versions of D&D should reference this RPG entry.
Any items written for the original (1974) D&D rules should reference Dungeons & Dragons (Original Edition).
Any items written for the Wizards of the Coast Dungeons and Dragons (released 2000) should reference Dungeons & Dragons (3rd Edition) (or later).
Due to the Old School Renaissance (OSR) Movement and the rise of retroclones, sourcebooks and adventures that were not specifically put out by TSR are now grouped under Basic D&D Compatible Product