platform-independent and allows you to change which keys do what later, without mak-
ing you change a lot of instances of “the Up arrow” in your design document. A
programmer who is implementing your control system does not care so much what the
literal key assignment for a command is, but she needs to know how many different
commands users will have and what game-world actions are associated with which
commands.
Once you describe how players command their game-world surrogate, the next
logical step is to describe the surrogate’s movement model. Does it follow a realistic
physics model or something more simplistic? Does it ramp up to full speed slowly or
does it achieve terminal velocity immediately? Does it move more slowly up inclines
than on flat surfaces? Is its responsiveness quick and tight likeQuakeor slow and pre-
cise likeTomb Raider?How does it react when it bumps into an object — slide off, turn,
or just stop? These are the sorts of details you will need to consider and describe in
depth.
It may be that moving game pieces or player surrogates around is not the key oper-
ation in your game. Think of what players starting a game would do first, and describe
that. If you were describingRailroad Tycoon, for instance, you would want to talk about
how players lay down track and the rules governing that. If you were writing the design
document forLemmings, you might want to describe how players can change a regular
lemming into a special lemming, such as a blocker or a digger. If you were describing
SimCity,you would want to explain how players zone an area.
If your game starts out with players needing to create their character, as they might
in an RPG such asDiablo, you will want to describe that process, summarizing the sig-
nificance of each statistic players must choose. What does “strength” or “dexterity”
represent? Later on in the Game Mechanics section, when you are describing an action
that is affected by a particular statistic, you will be able to refer the reader back to that
particular statistic’s original definition.
Chapter 19: The Design Document 363
RPGs such asDiablo II
often start the game
with the player creating
her character. Of course
this will need to be fully
described in the design
document.