Into the Tomb Lands, Level 2, Encounter 6 (Patreon)

Here's Area 6 of Level Two of my #Dungeon23 project, Into the Tomb Lands, for those who don't want to scroll through the Dungeon Level looking for new content.

6. The Sluiceway

The door to Area 6 has ancient runes noting it is dangerous, and not to be opened. The lower foot or so of the stone door and the landing in the shaft are covered in damp moss. The stone door was not designed to ever be opened again, and requires a Difficult engineering of thievery check to bypass or a few hours worth of typical Strength, Dungeoneering, or Digging check to crack open.

Either way, if the door is opened, exactly 18,000 gallons of water come rushing out of the hallway behind it. Realizing this is a risk is a Difficult trapfinding check before any work has been done on the door, or a Moderate check if some effort has begun to prepare to open it.

Anyone on the landing must make a Difficult reflex/dexterity/avoidance check, or take damage as if they had fallen 30 feet as the water slams into them, and gets sprayed off the landing and is immediately falling into the Deep. Anyone in the space in the shaft directly in front of the landing must make a Moderate check to avoid this fate, and anyone else in the shaft at the same level as the doorway or lower must make an Easy save/check.

If the PCs somehow get into the hallways without opening the door, in addition to finding it full to the ceiling with water, the find a Moderate water element swimming back an forth in the liquid in clear agitation. This is Undertow, a water elemental left to guard the hall and its (long ruined) contents. He essentially is in the same situation as An Ill Wind (Area 4).

Once clear, it becomes obvious water flows into this hall from a crack in the back wall at a rate of one gallon per minute. The crack is actually a crack in the fabric of reality, rather than just the rock, and leads to the Elemental Plane of Water. The pressure from it is so great the water cannot be held back by anything less than a giant stone door... like what sealed this hallway off from the Shaft.