Drunk Tank (3.5e Equipment)
From D&D Wiki
Name: Drunk Tank
Category: Enhancement for a city or castle wall.
The drunk tank is a feature that can be added to a city or castle wall during construction. The drunk tank is typically a small two foot by two foot room set into the wall. The room has a floor that slopes towards the outside of the castle and connects to a drain pipe that allows fluids to flow directly into the city or castle moat, river, or surrounding ditch. The door to the drunk tank locks from the outside and usually has a simple lock to which all the guards will have a key. The lock can be easily picked with by beating a DC 15 Disable Device check.
It costs 50 gp to add this feature into any ten foot section of wall during construction or 200gp to retrofit it into an existing wall.
Tidbits and interesting ideas: (herein follows ways you can work this into a campaign)
1. A particular drunk tank is the location of a message drop for a thieves guild, the PCs need to get in and they can do so by either breaking in or getting drunk and letting the guard throw them in.
2. An intelligent ooze has found the drain pipe and is using the drunk tank as an easy way in and out of the city.
3. A particular drunk tank actually contains a secret door leading into the castle dungeons.
4. A murderer has been putting his victims into the drunk tank to be found by horrified guards.