Single Entity Manipulation
The player controls a specific entity or avatar within the game. Any control the player exerts or actions he performs upon the game or its world take place through this embodied entity. In regards to this game element, the specific form or capabilities of this entity are less important than its function as an embodied point of contact between the player and the game. In fact, in some games, which game entity the player controls changes with time, outside the players control, like the players control over the pieces in Tetris (Pajitnov, 1986). Note that in such games, the player continues to directly control only one entity within the game at a time.
The method for controlling this entity can vary, some games providing controls that map directly to the entitys actions, some providing more indirect controls, such a system of menus, palette of on-screen buttons, or a language for constructing commands.
Games that use indirect controls such as menu systems shed some light on an important distinction between cursors and game entities. A game entity is an embodied something that exists within the games world. Other entities within the game can interact with that player controlled entity. A cursor exists outside the game world, without a body in that entities within the game cannot act upon a cursor. A cursor cannot be attacked or removed from the game due to damage, nor does a cursor act upon any game entity except to select it, allowing the player to then use game commands upon that entity, often by clicking on that command within a menu interface with the same cursor used to select the entity.
Sonic the Hedgehog
In Sonic the Hedgehog [Yasuhara, 1991], the player controls Sonic as he runs through levels filled with platforms, ramps, rings, and other items. Through Sonic, the player can perform actions on these objects. He can collect rings, remove enemy game entities, and activate bumpers. In this way, the player's power to influence the game world centers in Sonic and his representation in the game. He cannot directly control other entities within the game. He must perform any actions in the game world through Sonic.
The Legend of Zelda: The Wind Waker
In The Legend of Zelda: The Wind Waker [Aonuma, 2002], the player controls Link, guiding him about the game's world on a great adventure. The player's power to influence the game world centers in Link and his representation in the game. The game world is filled with other entities that the player cannot directly control, but some of which he can control through Link. For example, Link can move boxes around in the world by pulling them, changing their location. This results in the player having the ability to move boxes within the game, but only through Link. The player cannot manipulate the boxes directly on his own.
Angband is a freeware computer dungeon exploration game based (loosely) on the books of J.R.R.Tolkien. You explore a very deep dungeon, kill monsters, try to equip yourself with the best weapons and armor you can find, and finally face Morgoth - "The Dark Enemy" [Ben Harrison & Robert Ruhlmann].
Sim Meier's Pirates!
The vast majority of gameplay in Sid Meier's Pirates! [Meier 2005] revolves around control of a single avatar, although it should be noted that the avatar can change based on the actions being performed. When talking to non-playable characters and engaging in duels, the player is in control of the pirate protagonist. When sailing on the Caribbean and engaging other ships, the player is directly controlling a ship. Although the player can have a fleet of up to eight ships, only the ship designated as the flagship is directly controlled (the other ships simply follow). The only time when the player controls more than a single entity is during land battles, in which the player controls the entire pirate crew under turn-based combat.
In Tetris [Pajitnov, 1986], the player controls one tetrad on the game board at any given time, the tetrad in play being determined by the game software. After placing a tetrad, the player gets control over another tetrad, again chosen by the game. Using the tetrad under his control, the player can influence other tetrads by completing rows and removing those rows from play, but cannot directly control any tetrad that has already been placed.
Black & White
Black & White [Molyneux, 2001] presents the game in a first person god perspective that can be difficult to distinguish from the cursor interface used in many real-time strategy games. In many respects, the game's view resembles the view provided in an RTS, but the player's divine hand has properties beyond those of a simple cursor. It acts as a part of an implied, off-screen body whose eyes we are looking through. The hand is used to interact with game entities as a hand rather than as a cursor. For example, rather than simply selecting entities and telling them to move, players use the hand to pick them up, then put them down or throw them. The hand is also used within the game to reward or discipline one's creature, a special learning game entity, by petting it, slapping it, or handing it objects. Black and White's movement mechanics also reinforce the sense of embodiment by having players move themselves about the world by grasping hold of the landscape and pulling their implied divine mass through the game space rather than using a standard scrolling interface.
Aonuma, E. (2002). The Legend of Zelda: The Wind Waker. Nintendo, gamecube edition.
Harrison, B. Angband. http://www.phial.com/angband/
Meier, S. (2005). Sid Meier's Pirates!. Firaxis Games.
Molyneux, P. (2001). Black & White. Electronic Arts, windows edition.
Pajitnov, A. (1986). Tetris. Dos edition.
Ruhlman, R. Angband. http://www.thangorodrim.net/
Yasuhara, H. (1991). Sonic the Hedgehog. Sega, genesis edition.