Game Development Reference
In-Depth Information
Now let's suppose that only one person does both jobs. She mills enough to bake
three loaves of bread; then she bakes the three loaves; then she mills again; and so
on. This is an example of dynamic equilibrium: Conditions are changing all the
time, but they always return to the same state after a while because the process is
cyclic. If we tell the woman to stop baking and only mill for a while, and then re-
sume baking later, again the flour builds up. When she resumes baking, the system
settles into a new state of dynamic equilibrium (see
Figure 10.5
).
FIGURE 10.5
A new state of dynamic
equilibrium
Baking resumes
Cycles of milling and baking
Flour builds up
FLOUR
AVAILABLE
Baking stops, milling continues
Triggers
TIME
Dynamic equilibrium
When a game such as a construction and management simulation settles into a
static equilibrium, players can easily judge the effect of their actions on the system
by making one small change and watching the results. This makes the game easy to
learn and play. Dynamic equilibrium is more difficult for players to handle. With
the system in constant flux, it's hard to tell whether the changes players see result
from a natural process or from something they've done.
Settling into a state of equilibrium, static or dynamic, takes the pressure off the
player. She can simply watch the game run for a while and make adjustments when
she feels like it. Some construction and management simulations do work that way,
but most give the player more of a challenge. Rather than settling into equilibrium,
the designers build in a factor that requires the player to take action to prevent the
system from running out of some needed resource. To use our milling-baking met-
aphor, perhaps the player has to take action to keep the mill supplied with wheat. If
the player doesn't keep an eye on the wheat supply, both milling and baking come
to a halt. In
Age of Empires
, farms produce food automatically, but after a while they
stop working and the player must intervene to rebuild them. In
SimCity
, the roads
wear out and the player has to repair them.
Whether your system settles into equilibrium or runs down without player action,
one thing is certain: The player should always have to do something to obtain
growth—he should have to press on the gas pedal of your game, as it were. If the
