Game Worlds - Fundamentals of Game Design - page 88

2.5D , typically pronounced “two-and-a-half D.” This refers to game worlds that
appear to be a three-dimensional space but in reality consist of a series of 2D layers,
one above the other. StarCraft , a war game, shows plateaus and lowlands, as well as
aircraft that pass over obstacles and ground units. The player can place objects and
move them horizontally within a layer with a fine degree of precision, but vertically
an object must be in one plane or another; there is no in-between. Flying objects can't
move up and down in the air; they're simply in the air layer as Figure 4.2 depicts.
FIGURE 4.1
Super Mario Bros. ,
the classic 2D side-
scrolling game
FIGURE 4.2
StarCraft , with
plateaus and
lowlands visible