Open world
There is no consensus on what the earliest open world game is, due to differing definitions of how large or open a world needs to be. Ars Technica traces the concept back to the free-roaming exploration of 1976 text adventure game "Colossal Cave Adventure", which inspired the free-roaming exploration of "Adventure" (1980), but notes that it wasn't until 1984 that what "we now know as open-world gaming" took on a "definite shape" with 1984 space simulator "Elite", considered a pioneer of the open world; Gamasutra argues that its open-ended sandbox style is rooted in flight simulators, such as SubLOGIC's "Flight Simulator" (1979/1980), noting most flight sims "offer a 'free flight' mode that allows players to simply pilot the aircraft and explore the virtual world". Others trace the concept back to 1981 CRPG "", which had a free-roaming overworld map inspired by tabletop RPG "Dungeons & Dragons". The overworld maps of the first five "Ultima" games, released up to 1988, lacked a single, unified scale, with towns and other places represented as icons; this style was adopted by the first three "Dragon Quest" games, released from 1986 to 1988 in Japan.
Dungeons &amp; Dragons (1974)
The original "Dungeons & Dragons" boxed set was the first role-playing game, a fantasy system with a medieval European flavor. This set introduced concepts which would become standard, including abilities (such as strength, intelligence, and dexterity); character classes (fighting-man, magic-user, cleric) and levels; races (human, dwarf, elf, halfling); armor class; monsters and treasure; subterranean dungeons of halls, rooms, and doors replete with tricks and traps; and magic items, such as intelligent swords. The set also includes rules for wilderness travel by land and sea, hiring specialists and men-at-arms, building fortifications and setting up baronies. Movement rates and areas are given in inches, like that of the miniatures rules from which the system descended.