19 TRAPPED ROOM. The ceiling height is ten feet. In the center of the room is a raised dais with a small locked wooden chest. If it is opened or moved it will trigger a pressure plate and a portcullis will drop near the door, trapping everyone inside the room. If anyone is in the doorway when the portcullis falls, they must save vs petrification or take 1d10 points of damage.
After the portcullis falls, the room will descend eight feet over the next three rounds. While it is descending the characters may attempt to bend the portcullis bars or use another method of escape. When the floor has completely descended, there will be only one foot of air near the ceiling and mundane light such as torches, lanterns, or candles will most likely be snuffed out.
Those wearing armor may decide to abandon it or drown. Unarmored characters will be able to tread water for the time necessary. The room will stay down for one turn, then it will take another three rounds to re-ascend. The chest will lock itself again and the portcullis will rise. Any items which were discarded will have disappeared.
There are 100 gems in the chest, each is worth 1 gold crescent base value.