Chapter: Route-finding methods

Section: Default behavior with visited rooms only

By default, Approaches will find a route only through rooms already visited by the player, but it will ignore states of darkness. (A dark room never becomes "visited" until the player has seen it in the light, though, so this will not facilitate fumbling through dark rooms.) It also seeks a route first through unlocked doors and only attempts locked doors if that fails.

If we wish to change this behavior, we may do so by replacing the approach-heading selection rule, which currently reads thus:

    An approach-finding rule (this is the approach-heading selection rule):
        now approach-heading is the best route from the location to the noun through visited rooms, using doors;
        if approach-heading is not a direction
        begin;
            now approach-heading is the best route from the location to the noun through visited rooms, using even locked doors;
        end if.