Game Development Reference
member's jobs. This chapter concludes with a treatment of modeling emo-
tional states using techniques ranging from simple to sophisticated. The pro-
jects for the chapter start out with simple touches, progress to an FSM for
emotions, and finish with a relationship model loosely based on The Sims .In
prior chapters, we have shown that beginners can learn how to program game
AI for behaviors. In this chapter, we will show that modeling emotions can be
just as accessible.
As a programmer, you may be thinking something along the lines of, ''I'm a
programmer, not a psychologist.'' But the emotions we are dealing with make a
pleasantly short list. Our list, shown in Table 9.1, is taken from XEODesign's
research into why people play games [Lazzaro04]. They observed people playing
popular games and studied the players' responses and what triggered them.
Words with a non-English origin are marked. This list is not meant to be
exhaustive. For example, relief is not listed. Relief may be thought of as the
removal of fear or feelings of pressure. This list was also aimed at emotions that
come from sources other than story.
Table 9.1 Emotions and Their Triggers
Common Themes and Triggers
Threat of harm, an object moving quickly to hit player, a sudden fall or loss of
support, or the possibility of pain.
Sudden change. Briefest of all emotions, does not feel good or bad. After
interpreting the event, this emotion merges into fear, relief, etc.
Rejection, as with food or behavior outside the norm. The strongest triggers are
body products such as feces, vomit, urine, mucus, saliva, and blood.
Pleasure or pride at the accomplishment of a child or mentee. (Kvell is how it
feels to express this pride in one's child or mentee to others.)
Personal triumph over adversity. The ultimate game emotion. Overcoming
difficult obstacles. Players raise their arms over their heads. They do not need
to experience anger prior to success, but the accomplishment does require
Gloat over misfortune of a rival. Competitive players enjoy beating each
other-----especially a long-term rival. Boasts are made about player prowess and
Overwhelming improbability. Curious items amaze players at their unusualness,
unlikelihood, and improbability without breaking out of realm of possibilities.