All Work and Play - Game Invaders: The Theory and Understanding of Computer Games - page 165

• Permanence: A sign that can be recognized throughout its existence.
• Transience: A sign that can change its appearance, its signifi er, in some way
while still having the same signifi ed.
• Handling: A sign that can be controlled directly by the player through the
signs of intervention: keyboard, mouse, joystick, etc.
• Action: A sign that can cause changes to other signs.

To get some idea as to what we mean by these four characteristics, let's quickly run
through some of the signs in Pac-Man:

• The layout of walls and corridors are made up of signs that possess perma-
nence; they do not change and we always recognize them.
• The ghosts possess transience; we know the ghosts are made up of fi ve dif-
ferent signifi ers, only one of which is perceivable at any one time, yet we still
recognize individual ghosts.
• Pac-Man himself possesses handling; he is the only sign we can directly
affect.
• Pac-Man and the ghosts possess action; they are able to affect other signs in
the game: Pac-Man and the ghosts can be killed, the food and exotic fruit
eaten causing changes in the score, etc.

In this topic we take transience to be more than just a fl ickering light or revolv-
ing advertisement which has no causal relationship with any other sign. Such signs
would be layout signs, as you can see in Table 11.1. The point about CBS is that
not all signs possess all these characteristics and that all signs in a game fall into a
small set of classes according to those they do possess. The table shows this quite
clearly and simply.
We can see from the classifi cation in the table that we arrive at six classes of
interactive sign. The interactive sign possesses all the characteristics and identifi es
signs we use to intervene in the game. Actor signs possess all characteristics except
handling; they represent NPCs, doors and other autonomous and semiautonomous
game signs which can change other signs and be changed themselves. Controller
signs only have permanence and action; they are characteristic of such things as

Table 11.1 Classes of Computer - Based Signs

Class Permanence Transience Handling Action

Interactive * * * *

Actor * * *

Controller * *

Object * *

Layout *

Ghost *