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.
Adventure game
As computers gained the ability to use pointing devices and point-and-click interfaces, graphical adventure games moved away from including the text interface and simply provided appropriate commands the player could interact with on-screen. The first known game with such an interface was "Enchanted Scepters" (1984) from Silicon Beach Software, which used drop-down menus for the player to select actions from while using a text window to describe results of those actions. In 1985, ICOM Simulations released "Déjà Vu", the first of its MacVenture series, utilized a more complete point-and-click interface, including the ability to drag objects around on the current scene, and was a commercial success. LucasArts' "Maniac Mansion", released in 1987, used a novel "verb-object" interface, showing all possible commands the player could use to interact with the game along with the player's inventory, which became a staple of LucasArts' own adventure games and in the genre overall. The point-and-click system also worked well for game consoles, with games like Chunsoft's "Portopia Serial Murder Case" (1985) and Square's "Suishō no Dragon" (1986), both on the Nintendo Entertainment System using the controller input instead of text-based actions.