A Grate Slide

 

The floor in this hallway is made of highly polished oak planks.

Mechanical Trap

Halfway down the hallway is a trapdoor that runs the width of the hallway. It opens up into a metal chute. A DC 16 Wisdom (Perception) check reveals the seams of the trapdoor on the floor. Pressing down with a few pounds of pressure causes the trapdoor to open slightly. The trapdoor is 10 feet long and the width of the hallway. When a creature steps on the trapdoor, it opens up to a 60′ long metal chute at a 60 degree angle. 20 feet down the chute there is a 10 foot long section of raised grating, like a cheese grater. A DC 14 Dexterity saving throw must be made or the creature falls into the chute, taking 2d6 falling damage, and also suffering a +4 melee attack for 2d6 slashing damage from the grater. The creature ends up 52 feet below ground. Climbing back up the chute requires a DC 16 Strength (Athletics) check. The trapdoor can be disabled with a DC 14 Dexterity check, but requires something to wedge into it, like spikes or pitons.

 

Oil Door

 

A swollen wooden door is at the end of the hall.

Mechanical Trap

The inside of the door is made of a self sealing bladder full of oil. The doorknob operates a small drill that punctures the bladder. A DC 18 Wisdom (Perception) check reveals that the doorknob has a small opening which exposes some gears, which are oily. When the doorknob is turned, it sends a drill bit into the oily bladder, causing oil to pool under the door and on the other side. The oil creates a puddle in a 5-10 foot radius. When a creature walks through the door, it must make a DC 14 Dexterity saving throw or fall prone. Standing up requires a DC 14 Dexterity (Acrobatics) check. Otherwise, the prone creature may crawl 5 feet per round. The drill may be disabled by jamming or disconnecting the gears. This requires a DC 14 Dexterity check, and this check had advantage if thieves’ tools are used.

 

Anvil Trap

 

A long trap door is in the ceiling, with a pull rope hanging down.

Mechanical Trap

The trapdoor pulls down into a set of stairs to ascend to the attic. Balanced on the edge is a heavy anvil. If the rope is pulled, a DC 16 Wisdom (Perception) check allows the creature pulling the rope to sense a shifting weight from above. If the check succeeds, the creature gains advantage on the Dexterity check to avoid the anvil. When the trap door is opened, the anvil falls downwards. The creature opening the door must make a DC 14 Dexterity (Acrobatics) check or take 2d6 bludgeoning damage from the anvil. The trap can only be disarmed from the attic, and not from below. If approached from the attic side, no check is necessary to disable the trap.

 

Gas Room

 

The door to this large larder has been propped open.

Mechanical Trap

A metal rod extends out 2 inches from the floor, and holds the door open. The door opens out. On the other side of the door, powerful springs are present. A pressure plate in the room causes the rod to descend into the floor, closing the door. The room is filled with an unbreathable gas. A DC 12 Wisdom (Perception) check shows that the rod can retract, and a separate DC 12 Wisdom (Perception) check reveals the springs behind the door. The pressure plate can be spotted with a successful DC 14 Wisdom (Perception) check. The air in the room can be detected as not breathable with a DC 14 Intelligence (Nature) check from just outside the room. This roll has advantage if checked from within the room, and no check is necessary once the door shuts. When the plate is activated, the door swings shut. Those within 5′ of the door may either try to escape via a DC 14 Dexterity check, or stop the door from closing. A successful DC 12 Dexterity check followed by a DC 12 Strength check will keep the door from closing. However, as soon as the door is left unattended, it will shut. Once shut, it requires a DC 16 Strength check to open the door. The door can also be broken, and has AC 15 and 27hp. Those in the room once the door shuts will begin to suffocate after 1 round. The pressure plate can be disabled with a DC 14 Dexterity check, and the check has advantage of thieves’ tools are used. The springs on the back of the door can also be disabled with the same check, or broken. A DC 16 Strength check is required to remove them from the door. They can also be destroyed, and have AC 19 and 10hp. Once the door is shut, it must be opened or destroyed. The plate has no effect, and the springs cannot be accessed.

 

Pain of Glass

 

A ladder reaches up almost to a window just big enough to haul yourself through.

Mechanical Trap

The glass in the window above has been broken, and some jagged shards have been left in the window sill. The window is 20 feet above the the ground, and 5 feet above the top of the ladder. Small bits of glass below the ladder can be spotted with a DC 12 Wisdom check (Perception). Once a creature is within 10 feet of the window, a DC 14 Wisdom (Perception) check will reveal that a slight breeze moves through the window. If a creature climbs through the window by grabbing the sill, the sill makes a +2 melee attack for 1d4 piercing damage. If the creature is damaged, the creature must make a DC 14 Dexterity (Acrobatics) saving throw or fall, taking 2d6 falling damage.

 

Grater Doors

 

A wide doorway opens to the next room. It appears that there are two separate pocket doors that close together.

Mechanical Trap

This trap uses a pressure plate to trigger two spring loaded doors on each side to quickly close. The pressure plate runs the entire width of the door frame, and is as deep as the door frame. The inside of each door contains a metal grating similar to a cheese grater. The pressure plate can be spotted with a a successful DC 12 Wisdom check.  (Perception) It can be wedged open with a DC 14 Dexterity check with thieves’ tools. It will remain disabled for 1d4+1 rounds.  If no tools are used, the check has disadvantage. The plate can be disabled permanently with a DC 17 Dexterity check with thieves’ tools, and as before, the check has disadvantage without tools. A DC 5 Strength (Athletics) check will allow a creature to safely jump over the pressure plate. If the sides of the door frame are inspected, the grating can be made out with a DC 13 Wisdom (Perception) check. When the pressure plate is stepped upon, the doors quickly close. Those in the doorway must make a DC 14 Dexterity saving throw or be caught between the two doors. Those caught take 3d6 piercing and slashing damage. They are also restrained, and must make a DC 12 Strength (Athletics) check as a standard action to free themselves.

 

Razor Lid

 

This room has a long red wooden chest in the middle, flanked by couches. The top is flat, and a vase with dead flowers sits atop it.

Mechanical Trap

This trap has a single component. The lid is 2 inches high and sits flush on the bottom of the box. It can be easily lifted by prying a finger into the seam and lifting. However, along the entire seam on the lid runs several small razor blades that have been embedded into the wood. Irregularly placed pieces of metal can be seen from the side of the chest in the seam with a DC 14 Wisdom (Perception) check. A DC 14 Dexterity check is required to remove the lid without suffering damage. Anyone wearing any kind of armored gloves gains advantage on the Dexterity check. The razor blades deal 1d6 slashing damage.

 

Look Here!

 

The door is made of a stouter wood than the rest of the building.

Mechanical Trap

This trap has two components, a tripwire that spools out from inside the door itself, and a shiny ball of foil that is balanced above the door. The shiny ball of foil can be spotted with a DC 10 Wisdom (Perception) check and requires no check to remove. A small groove with the end of a wire can be seen along the right doorframe, about 6 inches off of the ground with a DC 14 Wisdom (Perception) check and can be cut and disabled with a successful DC 14 Dexterity check using thieves’ tools. If thieves’ tools are not used, the Dexterity check to disable has disadvantage. When the door is opened, the foil ball falls to the ground and the wire that is in the door frame spools out, anchored by the door and the doorframe. The creature opening the door must make a DC 12 Wisdom save or be distracted by the falling piece of foil, gaining disadvantage on all checks and saves for 1 round. The wire can now be spotted with a DC 10 Wisdom (Perception) check and can be avoided or removed with no check. However, if the wire is not seen, the creature must make a DC 12 Dexterity save or trip over the wire, falling prone when moving through the door.

 

Puncture Knob

 

The den is accessed by a large oak door. It has a single brass doorknob with a push-button in the middle.

Mechanical Trap

This trap has a serrated blade hidden behind the button. The blade is 1 inch long and mounted on a spring. It extends out 3 inches when the button is pressed. The edge of the knife can be see protruding through a small slit in the button with a DC 10 Wisdom (Perception) check, after which the knob may be opened and the spring mechanism disabled with a successful DC 15 Dexterity check using thieves’ tools. If thieves’ tools are not used, the Dexterity check to disable has disadvantage. When the trap is triggered, the creature pushing the button must make a DC 12 Dexterity Save, or take 2 slashing damage. In addition, until magical healing is used or a long rest is taken, the creature is at Disadvantage for any Dexterity based checks that use the hands.

 

April Fool’s Week – final trap: the trap gallery

A single day of devious trickery – er, that is to say, creative subversion of player assumptions – was never going to be enough for this blog. This week, a series of traps that will really mess with your players. Most are in fact so ridiculously rotten that their best use is to spring them, howl with laughter at the ensuing shrieks of outrage, and then retcon the traps out of existence once you’ve had your fun, lest your players mount an open revolt.

This trap bridges the more arbitrary, metagamey material of earlier in the week and our regular trap content. It takes place in a kobold warren, thieves’ guild, spy organisation’s base, or other suitable den of sneakiness.

The PCs’ goals require them to explore a section of the complex which is dedicated to showcasing traps. Laid out in a linear sequence are a series of rooms, and in each, the PCs find a different mechanical trap – all with clear instructions for how it works and how to bypass it printed on the door leading in, and all deactivated by some master switch. Careful examination of the traps indicates that they do indeed function as advertised, but are genuinely disarmed, and that the master switch for each trap is further into the complex – a cable in the walls and floor can be traced running further in, but it is on a hair trigger and interfering with it in any way will set off all the traps. (This cable should only be found through displays of truly extraordinary skill.) Further, once active, the traps can only be deactivated manually and individually – the override switch removes a series of chocks stopping the mechanisms from moving, but there’s no way to replace them all automatically.

Finally the PCs reach the end of the gauntlet of traps, and come across a door labelled “Trap Gallery Master Control Switch”. Opening the door reveals a room with periscopic (or magical) views into each trap chamber, and a big lever labelled “Trap Activation”. If the PCs are tracing the master control cable it does indeed lead directlyunder this door, and if the door is open they can see that it leads  towards the lever… but then loops around a pulley and heads back to the door frame.

The label “Trap Gallery Master Control Switch” is not saying what’s behind the door – it’s explaining that that the door is the Trap Gallery Master Control Switch – and opening the door causes all the traps to become active.

To get back out, the PCs will have to disarm all the traps they have just passed. The fact that the mechanisms include provision for a master override allows you to give them a small bonus on their rolls… and if they can successfully remember the instructions for how each trap worked, which were on the outside of the doors which are now at the opposite end of each room, you can give them a larger bonus. (This might be an occasion for the use of our upcoming supplement on memory in RPGs.)

We hope you’ve enjoyed our April Fool’s Week traps! Let us know in the comments.