Basically, a door that needs a password instead of keys. Unlike key doors, You don't need a key to get through. However, you need to be either told the password, or solve it urself. You could set up an interesting dungeon that requires u to find signs and stuff that give hints, which will lead to the end.
This is a really cool idea :D
i say NO!
i say NO! again
yup. another one for the plat door pile "sighs"