Poison Gas Trap
A grimacing stone mask with jade eyes is set 15 feet up on the wall.
Each time an eye is removed, a Failure is triggered.
Mask. A Perception check or an examination of the mask’s jade eyes reveals that the eyes are carved to fit inside the mask but are not attached to it. Each gem is worth 100 gp. An Investigation check reveals a faint noxious smell near the mask’s mouth. Examining the mouth reveals that the teeth are not particularly sharp or covered with poison, and that the mouth isn’t hinged and can’t close.
The mask is an object with AC 17, 30 hit points, and immunity to poison and psychic damage. Breaking it ruptures the cavity holding the poison gas, triggering a Failure.
- An eye can be removed from a distance with mage hand or a similar effect. A strong wind (such as gust of wind ) reduces the poison cloud’s diameter by 20 feet. If this reduces its diameter to 0 feet, the trap is disabled.
Potential Outcomes
Critical Failure or Failure. A hissing sound is heard as gas seeps into the area through the mask’s mouth. Roll initiative. On initiative count 10, a 30-foot-diameter cloud of gas emanates from the mask, spreading around corners. Each round on initiative count 10 for the next minute, the size of the cloud increases by 10 feet, to a maximum of 120 feet. A creature that starts its turn within the cloud makes a Constitution saving throw . On a failure, the creature takes 10 (3d6) poison damage and is poisoned until the start of its next turn. On a success, the creature takes half damage and isn’t poisoned. A creature can make a Sleight of Hand check to jam the eye back into the hole, disabling the trap and preventing the poison cloud from growing larger. Another object of similar size can be jammed into the hole with a Sleight of Hand check, but the check is made with disadvantage if the object isn’t an exact fit.
Success or Critical Success. The trap isn’t triggered.