addition, if a player who has landed on a planet stops playing and then after a while resumes, he or she can see visible changes in the sea level or the daytime/nighttime cycle. A form of simulated persistence referred to as "pseudo-persistence" has been used in both video games and pervasive games. Pseudo-persistence means making relevant world data available when the relevant players reconnect to the world instance. In a mobile game, a virtual world might exist on a distributed collection of mobile devices. If a player reconnects to a device they previously connected to, they find that their relevant world data is still present. In the video game Destiny, a World Server provides the persistent world data for the game instances (called "bubbles"), which are created on demand as a number of players are matched to play the game together.. The term 'persistent world' is frequently used by players of Neverwinter Nights (2002) and Neverwinter Nights 2 (2006) to refer to MMORPG-like online environments created using the toolkit. The first virtual worlds The first multi-player game to demonstrate on-line persistence was the text-based MUD1 written in 1978 by Rob Trubshaw and Richard Bartle. Initially only available for a few hours in off-peak time at Essex University, UK, it featured a world reset every 105 minutes. Nevertheless, it persisted independent of players logging in for the time it was running. The subsequent decade saw many on-line worlds clone this template, but all featured variations on timed resets and reboots or did not allow players to retain objects within the game other than running point totals such as treasure or experience points as a marker of progress. Avalon: The Legend Lives can be considered the first game to introduce a true persistent state world in 1989. Avalon pioneered the ability for items to be retained by the player whilst offline while the Avalon realm at large continued 24/7 with only a morning backup to mark the world pausing briefly. It is currently the longest running online virtual world. See also MUD Instance dungeon References Video game gameplay Esports terminology Virtual reality Massively multiplayer online games Online games