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.
Eamon (video game)
Brown encouraged players to modify and add to "Eamon", and published technical information on the game to assist them. "Eamon" is notable for being one of the first adventure games designed to be modular, with expansion packs written by users forming an integral part of the game experience. A master disk called the "Main Hall" is used to manage player characters and to facilitate their transfer between individual adventures. The character retains his or her attributes and statistics from adventure to adventure, as well as up to four weapons.
The game's interface is similar to that of most other text adventures — the game presents the player with descriptions of the character's surroundings, including events, artifacts, monsters and exits, then prompts the player to enter a command. These commands include such things as moving in certain directions (NORTH, EAST, UP, etc.), readying weapons, attacking, getting or dropping items, interacting with characters, casting magical spells or checking inventory.