VERBS AND OBJECTS - A Game Design Vocabulary - page 16

Creating Choices

Visualize Venus. An endless green sky, purple mountains piled on the horizons like clouds, a
yawning cleft like a mouth, leading into the smoking bowels of the planet. The Robot Mines.
Not mines staffed by robots—mines where humans dig for technology abandoned by a much
older, much more extinct, spacefaring race. Or where they normally do, except that today at
481,900 hours—Venus' days are much longer than Earth's—the unearthed robots suddenly,
simultaneously, blinked to life. Immediately and as one, operating under orders hard-coded
into their circuits millennia ago, they seized control of the mine and took the human workers
hostage—those that didn't manage to escape.

Now it's up to Janet Jumpjet, space-hero-for-hire, to explore the mines, incapacitate the robots,
and rescue the human hostages. She's armed only with her wits and the Megablaster 3000
Laser Pistol—shooting it is her primary verb.

What does it mean that Janet's main verb is “shoot”? Probably that there's going to be a lot of
gunfire in this game. Venus is a violent place. That's the future for you.

Janet's Megablaster fires a single laser bolt at a time—enough to melt one of those menacing
robots. POW! But firing the Megablaster generates a tremendous amount of heat—it takes half
a second to cool down between shots. This is a rule that we've designed. We probably spent a
lot of time playing with exactly how long the duration between shots is, tweaking the number,
playing the game, and trying to decide which made for the most interesting choices. We'll
probably tweak it a lot more before we consider the game done.

The duration between shots is part of the “shoot” verb. The rule: pressing the button fires the
Megablaster ahead of Janet at a rate of one laser bolt every half-second. Why is this important?
Because we can use rules to set up choices for players. A choice can be whether to shoot Janet's
Megablaster, or when, or where. If there's a half-second duration between shots—maybe that
doesn't sound like a very long time, but it's ages when you've got a crazed robot clanking
toward you—what choices does that create? Janet's pinned in a dark corridor, one that looks a
lot —there are two robots clambering toward her from two different directions.

Which one does she shoot first?

like Figure 2.2

Figure 2.2 Rules offer choices: shoot the left robot or the right one?

In fact, Space Invaders , the 1975 game of using a moving gun turret to destroy invading aliens,
presents the player with similar choices. In that game, the player can have only one bullet on