Conspicuous Secret Doors

Recently, I’ve been thinking about tutorials. The post/OSR milieu places great emphasis on player skill, but has not been good at creating skilled players except by a potent combination of attrition and player stubbornness. My conclusion: we need more tutorial dungeons. Lair of the Lamb and Tomb of the Serpent Kings are excellent, but Lair presumes a level-0 funnel and everyone in the scene has read Tomb. Skerples' 2017 point remains relevant eight years later: "It's like all the adventures we have are Bach concertos. People keep writing amazing works of staggering genius, but someone needs to write a book on how to play the piano."

This list of conspicuous secret doors is a teaching tool. Put these in the dungeon to tell players two things:

1. Secret doors exist.
2. Secret doors can be identified and opened through environmental interaction.

If you want to conceal them further, place extra clutter in the room. Searching a room for 10 minutes identifies presence of secret doors but expends resources and risks random encounter.

• Wooden doors can be destroyed with 10 minutes of hard labor, or burned.
• Stone doors can be destroyed with 10 minutes of hard labor, but require a pickaxe.
• Metal mechanisms can be destroyed with a single attack or manipulated by characters who possess some facility with devices.

Conspicuous Secret Doors

Conspicuous components are bolded.

1. Tapestry/rug conceals door/trapdoor.
2. Bookshelf slides away when false book “The Secret Way” pulled.
3. Brick sticks out of the wall. Pushing it back in opens a hidden door.
4. Wind blows through room from an illusionary wall.
5. Furniture piled against wall, concealing regular door.
6. Discolored plaster on wall seals up former doorway.
7. Grimy statue with polished bits often moved to open a secret door behind it.
8. Obvious lever opens a secret door elsewhere. Gears, ropes, and pulleys connect the two through buried channel in floor; rat-sized creatures can traverse it with ease.
9. Lighting an unlit torch causes nearby wall to swing open. 
10. Keyhole on wall, but door is well concealed and key is kept elsewhere.
11. Secret door left open by inhabitants who recently passed through.
12. Ivy has grown over the walls and doors, concealing any difference between the two.
13. A fireplace burns, but the room doesn’t fill with smoke. Where does the chimney go?
14. Water leaks into the room from beneath a secret door.
15. Brick pattern changes to allow a secret door to hinge.
16. Carved relief with socketed gems is a secret door. Pushing gems opens door, removing gems triggers trap.
17. Raised pressure plate opens secret door, but only while plate is held down.
18. Obvious door opens to brick wall. That wall is a secret door.
19. Pool of water conceals underwater entrance to another room.
20. Dark rafters conceal door high up in room.