Algorithms and Networking for Computer Games

human being or a random process will do, outwitting or outguessing the opponent becomes
an important part of the game.
Challenge and conflict aspects are enough for defining a game in an abstract sense.
However, in order to be played, the game needs to be concretized into a representation.
This representation can be a cardboard and plastic pieces as well as three-dimensional
graphics rendered on a computer screen. The players themselves can be the representation,
such as in the children's game of tag. Regardless of the representation, there must exist a
clear correspondence to the rules of the game.
Let us take the game of poker as an example. The players agree to follow the rules,
which state (among other things) what cards there are in a deck, how many cards one can
change, and how the hands are ranked. The rules also define the goal, having as good a
hand as possible when the cards are laid on the table, which is the player's motivation.
The other players are opponents, because they try to achieve a better hand to win. Also,
the randomness of the deck caused by shuffling opposes the player, who cannot determine
what cards will be dealt next. The game takes a concrete form in a deck of plastic-coated
cards (or pixels on the screen), which represent the abstractions used in the rules.
Apart from these formal features, the game play also includes subjective elements
such as immersion in the game world, a sense of purpose, and a sense of achievement
from mastering the game. One could argue that the sense of purpose is essential for the
immersion. What immerses us in a game (as well as in a book or a film) is the sense
that there is a purpose or motive behind the surface. In a similar fashion, the sense of
achievement is essential for the sense of purpose (i.e. the purpose of a game is to achieve
goals, points, money, recognition etc.). From a human point of view, we get satisfaction in
the process of nearing a challenging goal and finally achieving it. These aspects, however,
are outside the scope of our current discussion, and we turn our focus to a subset of games,
namely, computer games.
1.1
Anatomy of Computer Games
Computer games are a subset of games. To be more precise, let us define a computer game
as a game that is carried out with the help of a computer program. This definition leaves us
some leeway, since it does not implicate that the whole game takes place in the computer.
For example, a game of chess can be played on the screen or on a real-world board,
regardless of whether the opponent is a computer program. Also, location-based games
(see Chapter 8) further obscure the traditional role of a computer game by incorporating
real-world objects into the game world.
In effect, a computer program in a game can act in three roles:
(i) coordinating the game process (e.g. realizing a participant's move in a chess game
according to the rules),
(ii) illustrating the situation (e.g. displaying the chessboard and pieces on screen), and
(iii) participating as a fellow player.