Progression Mechanisms - Game Mechanics: Advanced Game Design - page 250

We can also do the converse and give the player a single key to unlock multiple
doors. The boomerang in the Forest Temple serves this purpose. Unfortunately, it
cannot be used to reorder the game space directly, because this potentially cuts the
level short and creates a problem for the player ( Figure 11.4 ). The trick to create
multiple locks for a single key, and still place those locks before the key, is to add
extra lock-and-key mechanisms ( Figure 11.5 ) or to mirror the multiple locks mecha-
nism with a multiple keys mechanism ( Figure 11.6 ).
FIGURe 11.4
Poor use of a single
key that opens multiple
locks: The player might
encounter the boss
before she finds the
sword.
FIGURe 11.5
combining multiple
locks for a single
key with an addi-
tional lock-and-key
mechanism