Here is a megadungeon module that’s slightly different: a Flood Trap. I described the idea some time ago, but haven’t used this location in play. It’s meant to be a side trip, a distraction, although if the players ignore some obvious signs, it can be deadly.
As with the other megamodules, you need filler areas connected to the exits around the module, which can be created with geomorphs or rolled randomly. In this case, the surrounding rooms can be anything; use other megamodules to define what they are. However, what’s above or below the trap are is important; there needs to be a water source above the area and a sewer level or sublevel of some kind below. I plan on doing megamodules for both as examples, but you could design your own.
Aside from wasting the player’s time if they figure out the trap (or wasting their lives if they don’t,) the area can serve as a difficult “back door” into either the level above or the level below. It would work well in a trap-themed sublevel, such as if you wanted to build your own Tomb of Horrors.
The module is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) license.
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