The Essential Information
- Main Info: The main trap information is in the DMG on page 120.
- Main Spell: Glyph of Warding (PH page 245) is probably the most common magical trap.
- Complex Traps: Use the complex trap rules (DMG page 121) for things like flooding rooms.
- Good List: Don't forget to check out the great trap list on page 297 of the DMG.
- Useful Spell: The Find Traps spell (PH page 241) helps but it doesn't point out the trap directly.
The book advises that in some situations, don't even roll. For example, if there is a pressure plate under a carpet, the hero automatically finds it if they remove the carpet.
Disabling Traps: This is dexterity-based (PH page 177). Some traps are mechanical, and some are magical. Each is handled a little differently:
- Disarming a Mechanical Trap: Int (Investigation) to figure out what to do, and then a Dex check with thieves' tools to disarm it.
- Disarming a Magical Trap: Any character can try to do this. Make an Int (Arcana) check, in addition to whatever it says in the spell description.
If you are proficient with these tools, you can add your proficiency bonus to disarming traps and picking locks. Here are some things that help characters with traps:
- (PH page 48) Danger Sense: Barbarians have advantage on Dex saves vs. traps that they can see.
- (PH page 97) Fast Hands: A third level thief has "Fast Hands" which means they can use a bonus action to disarm a trap.
- (PH page 98) Mage Hand: Arcane Trickster rogues can use "mage hand legerdemain" to disarm traps at range, which is really awesome.
- (PH page 166) Dungeon Delver Feat: This trap-centric feat gives you advantage and resistance to all sorts of trap-related stuff.
(lvl 2) Find Traps: (PH page 241) You sense traps within 120 feet. It only reveals that a trap is present. You don't learn where it is or exactly what it does.
(lvl 2) Alarm: (PH page 211) You create a warded area in a 20 foot cube. If any creature tiny or larger enters it, the 'alarm' goes off. It can be an audible noise that lasts 10 seconds or you can set it so it alerts you mentally as long as you are within a mile.
(lvl 2) Magic Mouth: (PH page 257) This lasts potentially forever. You set the trigger. When triggered, the mouth appears and utters a message up to 25 words. This is a very fun old school spell that I find very amusing.
(lvl 3) Glyph of Warding: (PH page 245) These are nearly invisible. Intelligence (Investigation) against the caster's DC to spot one. The caster decides what triggers it: touching it, getting close to it, etc. There are a couple different types:
- Explosive Runes: It explodes in a 20-foot radius sphere doing 5d8 damage of a type of your choosing. DEX save for half damage.
- Spell Glyph: You can store a spell of up to third level in this! Wow. Lightning bolt, fear or stinking cloud, whatever you want.
- Corridors are full of disorienting fog.
- Doors are locked as if by an arcane lock.
- Stairs are full of webs like the web spell.
- You can pick one more effect from a list that includes stinking clouds, magic mouths and more.
(lvl 7) Symbol: (PH page 280) This creates a glyph that is nearly invisible, just like a glyph of warding. The range on this is crazy. The symbol affects everyone within 60 feet! There are a lot of effects. I'll list a few so you can get the general idea:
- Symbol of Death: 10d10 necrotic, Con save for half.
- Symbol of Discord: Con save or bicker and argue for one minute. Victims have disadvantage on attack rolls/ability checks.
- Symbol of Stunning: Wis save or stunned for one minute!
Setting Trap DCs and Damage: (DMG page 121) This is the most important thing when making a trap. The charts on this page give you the numbers you'll need. For example, a trap that is deadly for a 7th level character has a DC of 14, a +7 to hit and does 10d10 damage.
Complex Traps: (DMG page 121) These traps execute a series of actions each round. It rolls initiative and can "take an action." The example given involves a flooding room. On the trap's turn, the water level rises.
Sample Traps: (DMG page 122-123) We are given a bunch of classic D&D traps like:
- Fire-Breathing Statue: Step on a plate, make a Dex save. Success = half damage.
- Spiked Pit: I am not seeing a Dex save to jump back, here. You just fall in and take damage. The way to avoid it is to spot it before you walk over it. Some spiked pits have poison that does an extra 22 poison damage!
- Rolling Sphere: The classic Indiana Jones trap. Step on a pressure plate, it rolls initiative. On the sphere's turn, it moves 60 feet. Creatures in the way make a Dex save or take 55 damage!
List of Trap Effects: (DMG page 297) This list is great. Tons of stuff you can use. Here's a few of my favorites:
- Collapsing staircase that deposits characters into a pit at its lower end.
- Pendulum, either bladed or weighted as a maul, swings across the room or hall.
- Floor collapses or is an illusion.
- Ages the first person to touch the object.
- Increases, reduces, negates, or reverses gravity.
- Releases, summons, or turns into a monster.
Positioning is Important
Marching Order: At the start of the session, have the group describe how they travel - who is in front, who is in back, etc. Tell them that unless you hear differently, that is the order. This way, when a trap hits, there is no question as to who is where.
Sidestep Metagaming: Let's say you have a room with a pit trap under a carpet. If you plop a map on the table and ask the players where they are, obviously they know something is up.
Also, if you suddenly go into detail about how there is a carpet in the room, the group might realize that you're describing this carpet for a reason.
Here's what works for me. I use red herrings. Sometimes, I will mention a specific detail or ask the heroes precisely where they are for no reason. This is done to keep them on their toes and to put a metagame mask on the rooms where it does matter.
Great D&D Traps
I'm going to list some of my favorite traps from previous editions.
White Plume Mountain
"Anything that alights on this silvery surface will move in the direction of its last horizontal impetus, bouncing off the walls (if it strikes them) like a billiard ball, until it slides into a razor-pit."
Fly spells and teleportation don't work in here. I ran this a few years ago and it was great.
Dungeon Magazine #41: Deadly Treasure
(Page 15) First Crawlway: All of the traps in this dungeon involve magic items. In this area, you need to crawl through a tunnel 3 feet wide and high. At the end of this tunnel, a "...thick cloth sheet seems to be stretched across the passage before you, barring further progress."
It's a giant bag of holding. It is stretched very snugly around the mouth of the crawlway.
If you puncture it in any way, 5 feet of crawlway and anything in it is sucked into nilspace and "quite likely lost forever."
As if that's not bad enough, anyone with a portable hole who gets close to the bag is gated to another plane with the hole and the bag.
Dungeon Magazine #97 - Life's Bazaar
(Page 59) The Gear Doors of Jzadirune: This adventure is the first in the Shackled City adventure path. It's written by Chris Perkins. The adventure involves a dungeon called Jzadirune, created by gnomes who were wiped out via a magical plague called The Vanishing.
This place is full of gear-shaped doors with different magic glyphs on them. Each glyph sets off a different effect including corrosive gas, flame jets, rays of frost, you name it.
The group needs to find keys in the shape of a rod. There's a different key for each glyph. You need to find something like 10 keys to safely traverse the complex. This entire dungeon is built around the trapped doors and I think it is really awesome.
I ran this back in 2008 converted to 4e and I didn't do a very good job. I really want another crack at it using 5e rules.
Draconomicon: Chromatic Dragons
(Page 158) Five-Headed Trap: I think this is the coolest trap I've ever used. Carved in the face of a cliff is a 150 foot tall carving of Tiamat. A huge pair of closed doors are set into the dragon's chest.
If you open the doors without uttering the pass phrase, all five heads breathe on the party at once! That's lightning, acid, poison, cold and fire. Each breath weapon has an aftereffect. Worst case, you are immobilized, burning and taking ongoing acid and poison damage until you make your saving throws.
I ran this trap in my Scales of War campaign. The heroes were level 29 at the time. They were on fire, running around and screaming like maniacs. It was awesome.
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