Action takes place within or in front of such digital
set pieces, and it is in this vein that volumes devoted to the artifi
cial intelligence (AI) of games carefully outline the behavior of
non-player characters (NPCs) and monsters (mobiles), but leave
the articulation of the game environment to artists.2 Nintendo’s old
Mario platform games exemplify this spatial hierarchy: although
the iconic plumber runs, bounces, and sometimes falls through a
series of obstacles set against a simple, side-scr