d20 Random Button and Lever Effects

 In the vein of my classic goo table and my more recent shrine procedure, I have come to value these workhorse lists and tricks that can be referenced or tacked onto the design of a dungeon space or scenario.

d20 Random Button and Lever Effects 

1. Self-Destruct. Room is destroyed, then the damage radiates at 1d4 rooms per Turn, increasing in die size on a 3 or higher.
2. Overload. Dungeon functions speed up and increase. 50% chance they malfunction after an hour. If no dungeon function, undead and constructs and so on become hyperactive. If no such creatures, a few walls explode.
3. Portals. 50% all doors and windows open. Otherwise they are stuck in their current position.
4. Dispenser. D6: water, snakes, acid, fire, treasure, supplies
5. Klaxon. Monsters approach. Make an extra encounter roll right away, but encounters are less common elsewhere in the dungeon for 1 hour.
6. Exit. d4: ejector seat, evactuation chute, whole room an elevator, teleportation rune.
7. Convenience. Activate internal furnishing. d6: fireplace, music box, sharpener, chamberpot, laundry, loom
8. Open. Hidden desk or door clicks open. 
9. Do Not Disturb. Defenses or signage deters random encounters.
10. Missive. Those in another room can hear and be heard by those in this room. 25% chance of a magical hologram granting vision.
11. Magic. Casts a random spell.
12. Lights. Illuminates dungeon with a random color.
13. Memento. Reveals a symbol, trophy, or art piece.
14. Screen. Displays dungeon information. d6: map, life signs, roster and biographies, history, inventory
15. Vent. d4: hot, cold, dry, wet.
16. Layout. Non-Euclidiciously rearranges a section of the dungeon, changing connections.
17. Relocate. Dungeon moves to a new spot 1d20 x 5 miles away at 1d100 miles per hour (1d100 x 2 kilometers per league, for European readers). d6: burrowing claws, muscular strides, crab legs, helicopter wings, slithering, pioneer boulder scooting)
18. Lockdown. Shuts off egress from another sector of the dungeon. Ingress unaffected.
19. Defenses. Designed to protect the button-presser, not harm them. d4: alligator pit trap, laser-eyed statue watches door, fiery perimeter, reveals weapon rack.
20. Launch. Fires ze missiles!

Overflow

• Capacity. 50% chance that dungeon denizens lose a special ability, like poison or infravision. Otherwise, they gain a new one
• Reset. Returns dungeon to original state, perhaps absent some important creatures and magic items.
• Gravity. Either deactivated or reoriented.