Meaningful Mechanics - Game Mechanics: Advanced Game Design - page 289

The inventory system introduced by Diablo is a good example of what might be
called an analogous simulation. The mechanics of that inventory system do not
resemble the mechanics behind the represented system directly, but the underlying
ideas are causally related. In semiotic terms, the inventory is an indexical sign.
Instead of trying to simulate all the details of an item, such as size, shape, and
weight, Diablo' s inventory system uses an item's relative size as its main restrict-
ing factor ( Figure 12.5 ). Each item takes up a number of inventory slots, and the
available slots are limited and organized in a grid. An item may take up 1x1, 2x2, or
1x4 slots, and so on. The player character can pick up an item only when there is
enough space for it in his inventory.
FIGURe 12.5
a Diablo -style
inventory
This type of inventory is an example of analogous simulation on games because
the main factors that limit what someone can carry in real life (shape, size, and
weight) are represented by easily understandable two-dimensional shapes. There is
a proportional relation between number of slots of the virtual items and the weight,
shape, and size of their simulated counterparts. The internal rules and constraints
of the inventory mechanics are immediately apparent and intuitive (not in the least
because they are tailored toward visual representation on a screen). Yet, the manage-
ment problems the system gives rise to are very much like those problems in real
life. The system even allows players to make an inefficient mess of their inventory,
teaching them something about the need to organize their property to fit more items
in their inventory—although some find this a tedious chore in a fantasy game.
The Diablo inventory system takes a lot of complicated real-world factors and
replaces them all by a single mechanism that is well suited to the medium of the
video game. Obviously some accuracy of simulation is lost (in Diablo an item can-
not be large and light at the same time), but the overall behavior is retained (the
players are limited in what they can carry). The cleverness of the Diablo inventory is
that it collapses all the nuances of managing an inventory into a size puzzle, which
is easily represented by a computer screen, instead of weight, which was the more
common choice in earlier games but which translates to the visual medium of the
computer less well.