Game Development Reference
In-Depth Information
Laying out some hypothetical costs:
Building a Barracks
500
Building a Tower
150
Repair Small Damage with Tower Present
100
Repair Small Damage without Tower Present
250
Repair Large Damage with Tower Present
250
Repair Large Damage without Tower Present
500 (new Barracks)
And some hypothetical probabilities of attack:
No Attack:
30%
Small Attack:
50%
Large Attack:
20%
If we lay out the possibilities as we did in the case of the computer warranty
scenario (Figure 7.7), we arrive at two utility values. Note that they are negative util-
ities because, in this case, they represent costs to us. With that in mind, we are look-
ing for the
highest
utility, that is, the
least
cost. Using the figures above, we find that
it would be better for us
not
to build a tower.
FIGURE 7.7
In this situation, we are not assuming a great probability
of receiving a large attack. Therefore, when we figure the cost of building
a tower plus the benefit that it provides, the utility is less than the
utility of not having one (and rebuilding the barracks if necessary).
For the sake of completeness, let's lay out the formulas themselves. We are now
solving for
E
(
T
), the estimated utility of building a tower.
