Look at Doors in DUNGEONS & DRAGONS in a New Light with THE INCREDIBLE WORLD OF DOORS & LOCKS
Your players approach a closed door. What do they see? How do they try opening it? What does the door hide? Chances are you’ve prepared an answer for two of those and your players are ignoring the prepared answer for the other. Well, to help give you some food for thought about doors, Martin Davico has created The Incredible World of Doors & Locks. This unofficial supplement not only talks about ideas for how to use doors but also provides tables for use to help you create doors and solve questions such as where any spare keys may be.
You can purchase The Incredible World of Doors & Locks from DMs Guild for $2.95.