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.
Electronic literature
In 1975–76, Will Crowther programmed a text game named "Colossal Cave Adventure" (also known as "Adventure"). Considered one of the earlier computer adventure games, it possessed a story that had the reader make choices on which way to go. These choices could lead the reader to the end, or to his or her untimely death. This non-linear format was later mimicked by the text adventure game, "Zork", created by a group of MIT students in 1977–79. These two games are considered to be the first examples of interactive fiction as well as some of the earliest video games.
The earliest pieces of electronic literature as presently defined were created using Storyspace, software developed by Jay David Bolter and Michael Joyce in the 1980s. They sold the software in 1990 to Eastgate Systems, a small software company that has maintained and updated the code in Storyspace up to the present. Storyspace and other similar programs use hypertext to create links within text. Literature using hypertext is frequently referred to as hypertext fiction. Originally, these stories were often disseminated on discs and later on CD. Hypertext fiction is still being created today using not only Storyspace, but other programs such as Twine.