It sounds as if the map is not just an augment to decision making
characters -- it is an agent inside the gamespace, capable of
independently (through dice randomizaion) of making "decisions" that
affect other agents. You could add new abilities to the map, hell
you could have the map engage in contests against the PCs.
- Hidden Design 17 -- Mysterious patterns discretely embedded in the
parchment show the route the map maker followed to sites of mystic
power
- Sinsiter Conspiracy 15 -- from time to time, the map directs the
characters to locations where agents of a sinister conspiracy have
been waiting for them
- Tempting Visions of infinite Wealth 4W3 -- the map has seductive
clues that suggest vast fortunes -- players must resist the ability
or be distracted from current tasks.