Locus of Manipulation
A games locus of manipulation is where the players ability to control and influence the game is located. In many games, the players manipulative powers are tied to either an on-screen or implied avatar, such as the on screen representation of Mario in Super Mario Sunshine (Koizumi and Usui, 2002) or an implied player avatar like in Doom (Carmack, 1993). In other games it is tied to a number of entities, whether anthropomorphic, as in Warcraft III (Pardo, 2002) or more object like, such as the tetrads in Tetris (Pajitnov, 1986). In all of these cases, at any given moment of play, the player exerts control over some game entity or entities, but not over others.
Secondarily, the locus of manipulation provided within a game can work with other aspects of the games presentation and rules to create a sense of identification between the player and the role he plays within a game, or Player Position (Costikyan, 1994). This is especially true in games where the player controls an avatar or a group of anthropomorphic entities. In Super Mario Sunshine (Koizumi and Usui, 2002), the game centers the players control and view of the world on Mario so as to lead the player to identify with Mario. In Madden NFL 2004 (Tiburon, 2003), the player is led to identify with the team he is playing, either as a team, favorite players, or in the capacity of coach. The game provides presentational and subgame modes to reinforce each position.
Carmack, J. (1993). Doom. id Software, dos edition.
Costikyan, G. (1994). I have no words and I must design. Interactive Fantasy, (2).
Koizumi, Y. and Usui, K. (2002). Super Mario Sunshine. Nintendo, gamecube edition.
Pajitnov, A. (1986). Tetris. Dos edition.
Pardo, R. (2002). Warcraft III: Reign of Chaos. Blizzard Entertainment, windows edition.
Tiburon, developer (2003). Madden NFL 2004. Electronic Arts, xbox edition.