How about a game where the geography and objects are created by
the player?  Everything starts out blank, and the player has a
bunch of labels, like "exit", "sword", etc., which can be used to
identify things. I wonder if this can be done using current zork
technology?  Note that the vocabulary is already there, it's just
the changing of the various tables for objects that's new.

This could also just be a problem in some other game; a blank area
that you have to fill in "properly" (perhaps with magic?) to solve
a particular problem.

One way to actually work this would be to have an object called
FORMLESS-OBJECT, and then swap in the real object associated with
the name given it by the player.