Game Development Reference
In-Depth Information
In a CMS, the player tries to understand and control a mathematical model—
although that's not the way you will present it to her. She needs convenient access
to key variables within the model. You should display the most important
scalar
variables
(
single-value
variables)—for example, the amount of money she has to work
with at the moment—on the screen at all times. The display can show digits if
that's most appropriate or a bar graph or some other kind of graphic device,
depending on the nature of the simulation.
Often the player needs to know not only the current value of a variable, but also
how that variable has changed over time. This lets her track and respond to trends
before trouble occurs. In
Theme Park
, visitors come into the park, spend time, and
leave again. The player can see them wandering around but has difficulty getting a
sense of the park's popularity just by counting heads. The player can bring up a
graph to see how the population has changed over the past 1, 3, or 12 game years
.
With
vector variables
(
multivalued
variables), you need a different approach. In
Caesar,
for example, the player builds a Roman town. Every area of the town needs
a water supply of some sort, whether a well, pipe, or fountain. The amount of water
available throughout the town is a vector variable, having a separate value for each
square on the town grid. The game's default perspective shows all the buildings
and all the water wells and fountains and so on, but it makes it difficult for the
player to visualize exactly which areas are served by water supplies. To get a clearer
picture, the player can bring up a different view of the game world that hides all
the buildings except for the water supplies and shows a blue overlay over the rest of
the town. The shade of blue in each area indicates the amount of water available
there, from light blue indicating little water to dark blue indicating plenty.
You must provide the player with these k inds of analy tical tools so she can under-
stand what's going on inside the simulation.
SimCity
supplies several types of
overlays that inform the player about fire danger, crime, pollution, and so on.
These tools allow her to quickly locate trouble spots and to respond. These kinds of
map overlays should not be snapshots that freeze a moment in time, but rather
they should be continuously updated by the simulation. That way the player can
watch them for a while and tell whether particular situations are getting better or
worse—and most important, whether her actions are having the desired effects
.
Summary
Construction and management games are about processes. They fulfill a desire to
create and manage a world, and you should make sure to give the player plenty of
tools to do it with. Economics plays a primary role in the game mechanics, and if
you spend time making a solid economic system, you will find the remainder of
the game easier to create. You must consider how the player controls the processes
in your game and how she comes to understand the current situation through the
user interface.
