Advanced Dungeons & Dragons 1st edition refers to an edition of the Dungeons & Dragons roleplaying game rules released by TSR between 1977 and 1989. It is commonly abbreviated AD&D 1e, or simply 1e.
Despite its name, it was not the first ever version of Dungeons & Dragons released; that honor goes to Original Dungeons & Dragons, which preceded AD&D and was published from 1974 to 1976. AD&D 1st edition was succeeded by Advanced Dungeons & Dragons 2nd edition in 1989.