Game Development Reference
In-Depth Information
As Chapter 8, “User Interfaces,” explains, the user interface links the input devices
in the real world to actions that take place in the game world.
Actions
, in this sense,
refer to events in the game world directly caused by the user interface interpreting
a player input. If the player presses a button on a game controller and the user
interface maps that button to striking a cue ball in a game of pool, striking the cue
ball constitutes an action. If the cue ball knocks another ball into a pocket, that is
an event, but not an action; the movement of the other ball is a
consequence
of the
player's action.
Actions are the verbs of the game, and the way in which the player usually thinks
about his play: “I run, I jump, I punch, I buy, I build.” On arcade machines, each
input device is usually labeled with a verb: Fire, Boost, and so on. When you define
the player's role in the concept stage of game design, you should make a list of
some of these verbs. If the player's role is to be a cowboy, what does a cowboy do?
Don't think in high-level terms (“protect the cattle”) but in terms of verbs that
might be assigned to input devices (“spur the horse,” “fire his gun,” “sell a cow,”
and so on.)
NO HIERARCHY OF ACTIONS
Challenges are explained in terms of a hierarchy because that hierarchy remains in the
player's mind throughout the game, a collection of goals that she works to achieve. You
might think, then, that there should be an equivalent hierarchy of actions
—
that if the
game presents the high-level challenge “try to defeat the boss monster,” there should be
a high-level action called “defeat the boss monster.”
Actions aren't in a hierarchy because a hierarchy of actions doesn't benefit either you or
the player. Making up an artificial high-level action (defeat the boss monster) to go with
a high-level challenge isn't terribly useful. If you tell the player, “To defeat the boss mon-
ster, perform the defeat the boss monster action,” she hasn't learned anything. There's
no such button on the controller, so what good does it do her?
Instead, actions are defined in low-level terms, as events resulting directly from the play-
er's use of the control devices. In fact, a game's tutorial levels often teach players how to
defeat monsters not in terms of game actions but in terms of real-world button-presses.
Tutorials say, “Attack monsters using your punch, kick, and throw shuriken buttons.” It's
up to the player to figure out how to combine these to defeat the boss monster.
Actions for Gameplay
Most of the actions that a player takes in a game are intended to meet the chal-
lenges that she faces. This topic cannot possibly provide a list of all the kinds of
