Game Development Reference
Imagine someone asks you to paint 10 houses. There are no depen-
dencies in this task. It doesn't matter in which order you paint the houses
because the way you paint one won't affect how you will paint the others.
Game design isn't like this. Different parts of a design are often in-
terdependent. The artistic look of a level depends on the layout of that
level. The layout depends on the player's tools. The player's tools depend
on the basic interface. If any element changes, so must every element that
depends on it.
Understanding dependencies help us reduce the risk of finished work
having to change because of changes in something it depended on. For
example, imagine we spent the time to fully animate a character that runs
at 5 km per hour in every direction. If we later decide that he must move
at 7 km per hour, all those animations must be redone. The animation
art depended on the design of the movement system for the character; a
change in the movement system rippled into the animation content and
destroyed good work. Had we understood our dependencies better, we
might have solidified the movement mechanics (in graybox) first and done
the animations later.
The Dependency Stack
To understand the dependencies in a design, designers can draw a depen-
dency stack .
A DEPENDENCY STACK is a simple analysis method that identifies key
dependencies among design elements. It helps us know what to work on
now and what to leave for later.
To build a dependency stack, we start with a game design. The design
may be a paper plan at the start of development, or it may be partway im-
plemented and tested. We break the game apart into individual elements—
mechanics, controls, interfaces, and subsystems. Then we identify key
dependencies among these elements. Finally, we draw out a graph illus-
trating all the dependency relationships. This is the dependency stack.
Let's look at an example. Pretend we're making Fantasy Castle , a
lighthearted construction game about building a castle in a fantasy world.
Fantasy Castle just started development, so the design team is long on
ideas but short on tested, proven designs. They've written out a long design
document. Each of the 22 subsystems has a fleshed-out paper design. Here
are summaries of them, in no particular order:
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