What we need here is completeness of the universes we create. Such completeness is only obtained through closure. A good game design presents a closed and complete universe. Leave out the petty things so that you can do the important features completely. Thus, one desideratum of game design is parsimony.
Parsimonious design decreases user expectations.
The user interface manifestation of this problem is the text parser. A parser suggests to the user that any valid English expression will be accepted by the parser. This is a cruel falsehood to perpetrate on a user. To place this expectation on our users is unwarranted. Increasing accessible states I now turn to the happier solution of increasing the number of accessible states.