Box of Brown Mold (CR 2)
Type mechanical; Search DC 22; Disable Device DC 16
Trigger touch (opening the box); Reset automatic
Effect 5-ft. cold aura (3d6 nonlethal cold damage)
Market Price 3,000 gp
The trap is ingenious; nothing is as effective as a trap triggered by the victim’s curiosity. The average damage dealt makes this barely a CR 2 trap. The trap isn’t actually a CR 2 trap, though; it is a CR 3 trap, because it affects everyone within 5 ft. of it and multiple targets increase the CR by one. The Disable Device DC makes no sense, opening the box triggers the mold: how can one disable the mold?
To make the box more effective, let’s use what we already know of brown mold…
Box of Bursting Brown Mold (CR 2)
Type mechanical; Search DC 24; Disable Device DC 15
Trigger touch (opening the box); Reset none
Effect 5-ft. cold aura (3d6 nonlethal cold damage); multiple targets (all creatures within 5 ft. of the 10 ft. square area covered by the bursting brown mold)
Market Price 1,600 gp
As always, fire is a trapsmith’s friend. A flask of alchemist’s fire bursts open when the box is opened. This immediately increases the size of the brown mold to 10 ft. in diameter; everyone within 5 ft. of that area suffers 3d6 nonlethal cold damage.
Disabling the box of bursting brown mold means that the flask of alchemist fire fails to open when the box is opened. If disabled, treat the box as a standard box of brown mold.
By making this a one-shot trap (no reset), we can reduce the cost of the entire trap, and it pays for the increase of the Search DC. The multiple targets should increase the CR by one, but the low DC of the Disable Device check compensates for that.
Slime-Slinging Trap (CR 5)
Type mechanical; Search DC 24; Disable Device DC 29
Trigger location; Reset automatic
Effect atk +5 ranged touch (green slime); multiple targets (1d4 attacks on every target in a 10-ft. square)
Market Price 15,500 gp
The box of brown mold trap proved quite successful, and this led to the creation of several other traps founded on the principle of biological warfare. The slime-slinging trap is one these creations.
Spinning spoons, made from stone, dip into a reservoir of green slime, flinging gobbets at every target in a 10-ft. square. Multiple hits do not increase the effects of green slime.
(This post is Product Identity.)