In a mosquito infested swamp where the Cotton Mouths slither, there lies an abandoned temple. Nobody knows what happened to the Snake Cult that lived here and there is little left to mark their passage.
A one-shot adventure for 4 level 2 characters.
In addition to the main temple building, there was once a dorm building where the acolytes lived together and four smaller dwellings where the priests each had their own space.
As the swamp waters rose, the dorm and the individual dwellings became partially submerged in the waters. The doors are swollen shut but are rotted to the point that it wouldn’t take much effort to break them down. Anything inside these buildings of any interest rotted away many years ago.
The main temple had been built well up from the ground and is still above the water level and is currently home to 5 Giant Poisonous Snakes that are concealed in the leaves and debris that litter the floor, and they are very territorial.
At the back of the main temple, behind the altar, are some stairs leading down to the underground level. The stairs exit into area 4 in the below ground map.
The floor in this area is flooded with murky water about 1 foot deep. The water is deepest in the “tail” end of the map (near room 1). The floor level raises a bit towards the “head” end of the map (room 13) where it is only a few inches deep.
Since this dungeon has been long abandoned, the only inhabitants of this place are the undead and some snakes.
Room 2 is a library but all the books are rotted away. There is a secret door (DC 10 to spot) to room 1. The door triggers a poison arrow trap (the cultists were fond of their poison) that fires when the secret door is opened (DC 15 to find the trap. Dex save DC 12 to dodge. If hit, DC 12 Con save. On a failed save, applies Poisoned status for 1 hour. Successful save means no poison). There are more library books in room 1 as this was where the priests kept their more valuable books. Again, most of them are rotted away, but there might be a few salvageable books or scrolls here suitable for the characters level.
There is a pit trap at location 3. Keep in mind that nearly 1 foot of murky water covers the trap, so is very difficult to spot (DC 16). Fortunately, being underwater means that the pit is full of water and you only have to swim to the other side. Just watch out for the 4 Poisonous Snakes that come out to say “hi”.
Area 4 is the staircase to the temple above. There is 1 foot of murky water at the bottom of the stairs.
Rooms 5, 6, and 7 are old studies and bedrooms for the highest-level priests. This would make great spots for some skeleton priests.
(I honestly forget what I had planned for the trap at location 8. Another pit trap would be boring, so maybe a Gelatinous Cube living here instead of a trap.)
The trap at location 10 (DC 14 to spot) is a combination alarm and Net trap. The net falls from the ceiling covering the 5ft by 10ft area indicated on the map. The net restrains anybody under it when it falls, while the alarm bell alerts some skeletal warriors in room 11 who come out to attack while the party is distracted by the net. If the players enter room 11, more skeleton warriors emerge from rooms 9 and 12, attempting to surprise the party (DC 12 stealth).
Room 13 is where the treasure is, on the raised platform in the centre of the room. The water is only an inch deep here and the platform is raised above the water level and is dry.
The trap in room 13 is another water-filled pit trap, but since the water is much shallower here, it’s easy to spot (DC 11). Spotting the trap might help because it is where a Giant Zombie Constrictor Snake lives. The snake is not a pretty sight, with layers of skin peeling off and snake rib bones poking out.
Map of the above ground temple. Note the insert in the top right of the map also shows the location of the dorms.