Fair enough! I think keys would be a better option, probably, because at present the minimum length condition never comes up (all my words are 8+ letters anyhow because that's how long the path is). Maybe you could have to meet some other condition to open the door, like using a certain number of duplicate letters in a word, or using a verb, or using a palindrome, etc? That way there's something other than path length to consider. I don't know how dictionaries for word games work, though, so that might be a stupidly massive amount of work for interesting criteria, in which case keys may well be a better option.