Core Mechanics - Fundamentals of Game Design - page 317

STUDY YOUR ENTITIES
Once you have a good grasp of your resources' sources, drains, and conversions,
move on to your entities. Go down your list of entities and ask the following ques-
tions about each one:
■ Does this entity store an amount of a resource, and if so, have I already docu-
mented how it works in the previous step?
■ What events, processes, and relationships affect the entity? What conditions
apply to these events, processes, and relationships?
■ What events, processes, and relationships does the entity contribute to? What
conditions apply to them?
■ What can the entity do by itself, if anything? Any entity that can do something
by itself—whether the entity is as simple as a detector or as complicated as an
NPC—requires mechanics to define what it does and how.
■ What can the player do to the entity, if anything? If the player can manipulate
the entity, he requires an action to do so, and actions require mechanics.
■ Is this a symbolic entity? If so, it requires mechanics to control how the entity
gets into each of its possible states.
Many of the verbs in your list of verbs will be associated with particular entities, so
as you examine an entity, check to see which verbs apply to it and what mechanics
they imply.
ANALYZE CHALLENGES AND ACTIONS
Go over the list of challenges and actions that you intend to offer in each gameplay
mode. All the active challenges and each action must have an associated mechanic
and possibly some associated data. (If it requires data, you should already have an
entity defined for it.) How does the action affect the world? How does the challenge
affect the avatar or the other entities under the player's control? Use the answers to
these questions to document your mechanics.
LOOK FOR GLOBAL MECHANICS
Global mechanics operate all the time, regardless of what gameplay mode or level
the game may be in. Global mechanics include those that implement actions such
as pausing the game or, if the player can win or lose in more than one gameplay
mode or level, detecting the victory or loss conditions. (In many games, the level
designers specify a different victory condition for each level, but the loss condi-
tions—such as running out of money or health—remain the same in every level.)
Go through your list of verbs and see how many of them describe global mechan-
ics, and then define how each works.