Game Development Reference
In-Depth Information
MECHANICS OUTSIDE THE INTERNAL ECONOMY
The internal economy of a game includes those resources and mechanics that the player
knows about and tries to manipulate. These include data that may be displayed by the
user interface or that form part of the victory and loss conditions. Designers generally
do not consider those mechanics over which the player does not exert control to be part
of the internal economy. The mechanics that define the AI of nonplayer characters, for
example, make up part of the core mechanics but not part of the internal economy of
the game.
A mechanic governing avatar and vehicle movement may or may not be considered part
of the internal economy, depending on whether movement produces or consumes any
resource. A serious car racing simulation treats fuel as a resource that the engine con-
verts to kinetic energy (another resource) as the engine drives the car forward. The
brakes consume kinetic energy, slowing the car down, and this wears out the brakes.
Only the most realistic racing games bother to simulate fuel consumption, kinetic energy,
or brake wear, and in those games, such factors can legitimately be considered part of
the internal economy. Less sophisticated vehicle simulations make the vehicle stop and
go at the player's command without incorporating any concept of resource production or
consumption. Similarly, in most games featuring a humanoid avatar, the avatar can walk,
climb, jump, and fight indefinitely without ever needing food; these processes do not
consume anything. For the most part, then, the mechanics of movement don't form part
of a game's internal economy unless the physics simulation is sophisticated enough to
justify its inclusion.
Sources
If a resource or entity can come into the game world having not been there before,
the mechanic by which it arrives is called a
source
.
In a simple shooter, the game begins with some resources, such as enemies, already
in the game world, but more enemies may appear at
spawn points
. A spawn point is
a designated location where the core mechanics insert new resources into the game
world and therefore into the economy. Enemies are part of the economy, a resource
that is produced at spawn points and consumed by conflict with the avatar. Each
spawn point is governed by a mechanic that specifies its location, what kind of
resource it generates (spawn points in shooters can also produce weapons, ammuni-
tion, or health packs), and at what frequency.
Sources often produce resources automatically (or at least produce resources auto-
matically once the player starts them going, for example, by building a factory).
You will need to define a
production rate
, either fixed or variable, and different
sources may produce the same resource at different rates. In
The Settlers
games, riv-
ers produce fish at a constant rate. A mechanic also defines the maximum number
