pervasive game can be divided into three temporal phases: "pre-production", "run-time", and "post-production", but because we are dealing with games these phases can also be referred to as "pre-game", "in-game" and "post-game", leaving the word "run-time" to mean that the game is running, but players are not necessarily playing. Because pervasive games make use of technology, the technology is started during or at the end of the pre-game phase and left running throughout the in-game phase. The pre-game phase is usually used to reconfigure or author the game to a particular context, for example a location. Reconfiguration of the game can extend into the in-game phase. The post-game phase is often used to debrief players and perform analysis of the game for further stagings. While players are playing in the in-game phase, the game can be continuously altered through the use of game mastering. Because pervasive games take place in the physical world, another responsibility of the game master is to keep players safe in the highly variable, possibly dangerous conditions of the physical world. A drawback of game mastering being that it can require a significant amount of human resources. In order to support game mastering, tools can be used to automate the process. Such tools, among other things, can help process the potentially massive amounts of event information game masters must deal with. Two ways a gamemaster can influence the flow of the game: by directly altering information in the technology guiding the game, or by communicating directly with the players. Classification Pervasive games have been associated with ubiquitous games, augmented and mixed reality games, mobile games, alternate reality games, (enhanced) live action role playing, affective gaming, virtual reality games, smart toys, location-based or location-aware games, crossmedia games and augmented tabletop games. The book Digital Cityscapes categorizes "playful activities that use mobile technologies as interfaces and the physical space as the game board" into four categories; pervasive games is said to be the most general, with urban games, location-based mobile games and hybrid reality games being successively more specific. Another subclassification of pervasive games is based on to what degree technology is utilized in the game. A pervasive game is said to be "technology-sustained", if the game relies on computer simulation, in other words, "the computer maintains the game state through monitoring and reacting to player activities". In contrast, "technology-supported" pervasive games use technology, but it is not