Directions-as-objects seems to be a common pattern. LambdaCore does the same thing, though LambdaMOO later added a Generic Detailed Room with basic support for

Directions-as-objects seems to be a common pattern. LambdaCore does the same thing, though LambdaMOO later added a Generic Detailed Room with basic support for directions, so a separate object wasn't required. (Anything more sophisticated than "go west" still requires a separate door object.) In addition to missing checks causing unexpected interactions, this approach also has the problem that the two ends can become asymmetrical, causing confusion (though this may be desired e.g. in the case of a trap-door). In the case of LambdaMOO, there's an entry northwest from the living room to the kitchen, but no corresponding entry southeast in the other direction!