On Traps

Murphy Barrett
The Dungeon Deep
Published in
6 min readMay 25, 2020

I think a lot of traps are incredibly poorly implemented in D&D, and most games. They’re designed to be game challenges. But that’s not how traps really work.

Traps have three purposes in the real world.

  • Kill or Capture something
  • Deny terrain or limit mobility of an opposing force
  • Keep people out of somewhere

Instead, most traps are implemented like game puzzles, which is horribly unrealistic.

We can add a one purpose appropriate to a heroic fantasy setting. Proof of Worth.

So when traps are implemented in games, consider why is a trap there at all? If the trap is to limit the mobility of an enemy force in order to deny them a particular bit of real-estate or force them into favorable terrain for an ambush, then the trap should be lethal with no warning.

If the Pinelandians have laid out a minefield, magical or mundane, it’s not there to be a challenge to beat. It’s there to kill anyone who goes through it, either through the direct effect of the mines, or by pinning down whoever gets caught in the minefield so that they can be killed through direct or indirect fire.

Of course, you can let your players spot the signs of a minefield, or whatever the trap is. Dead animals, disturbed earth, etc. But if they trigger the trap, that’s it. Kaboom. Spike to the face. Foot blown off. Whatever. The only survival condition is to notice and disarm or avoid the trap in the first place.

Either way, the trap should not be designed to be annoying. It should, depending on the aim of those who laid the trap, kill or maim. Not just knock a few hit points off and Bob’s your uncle.

This applies to hunting traps as well, though they may simply snare the PC, not kill them outright.

If the purpose of the trap is physical security of a particular place, again, there shouldn’t be riddles or clues. Such traps are designed to keep people out or kill anyone who makes it inside. There should be no easy riddle to get by the pillar of death. Because anybody who is supposed to be there already knows how to get by it. They already know to speak “Friend” and enter.

Traps designed for physical security should already be known to whomever set them up, or the members of that group. Therefore there should be no deliberate warning that they’re there. Fail to notice, and you’re just dead. Or captured.

There is an exception for locks. But not giant stupid puzzle locks.

This is not a lock sane people would devise. This is a sane lock.

So is this.

So your door has a magical keypad. No riddles. The right people already know the code. Input it wrong, and you just don’t get in, or the alarm spell starts screaming, or the fireball flashes outward, etc. That the lock/keypad is there is all the warning the players ought to have that there is a “trap”.

If you want to go Egyptian Tomb style on this, the tombs were known for being rather elaborately trapped. But some of the traps were simply false entrances. Go down one of those, and you simply die without warning. Why? Because anybody who is supposed to be there already knows that that entrance isn’t the real one.

The Proof of Worth is a bit different. The proficient one will come, but the temple builders don’t know who that is, only that s/he will come. And only in this instance are riddles and suchlike appropriate.

https://www.youtube.com/watch?v=NkGTyndJC1w

And as we can see in the Indiana Jones example, the Worthy shall pass, and the unworthy shall die. Not take 1d4 damage. Die. Roll vs Decapitation.

Now, with the purpose of traps understood, here are some traps you could use in a game.

Trap 1

The party is attempting to ambush a hobgoblin patrol as they lay up for the night.

The party sneaks forward, and miss their spot checks. Someone hits the tripwire. A horrible screaming sound erupts from nearby, and a blazing light blinds everyone. They’ve run into a trip-flare.

It can be magical, alchemical, whatever. The effect of which is that the hob camp is alerted (no surprise round) and the party is blinded for a round or two, as their night adapted eyes are suddenly assaulted.

Trap 2

The party is moving down a dungeon corridor. The dungeon is known to be inhabited by hobs (because why not). The Rogue passes his spot check.

“You observe midway down the hall a few scattered blotches of brown amidst the grey stones.”

“Hey, guys, don’t old bloodstains look rusty brown instead of red? Um…okay, so Jax (the rogue) sneaks down the hallway five feet away from the blotches for a closer look.” Roll search, and pass

“Jax, this close you can see very small cutouts on one side of the hallway, hidden by irregularities in the wall, and small divots opposite them.”

So they’ve had the chance to spot the impalement trap that the hobs keep resetting every time a party of adventurers dies. And it’s a properly lethal trap. If Jax fucks up and trips it, he’ll probably die. But now he has a chance to figure it out first.

Trap 3

The Rogue is now trying to pick a lock into the Baron’s storeroom. Roll a failure.

“The lock rotates (he thinks he’s passed!) and you feel a sort of impulse from the locks as you hear a twang. Your lockpicks are now broken.”

There’s an iron bar in the lock mechanism. If a proper key isn’t used, rotating the lock actuates the bar in a sort of scissors like action.

Trap 4

This one is if you want to be a bitch. The idea comes from another trap I read somewhere, I forget exactly where.

The players come upon an obvious trap puzzle. A verbal riddle, moveable painted panels, whatever. Just copy any obvious video game trap you like. You should have some dead bodies lying around as testament to those who failed.

Your players do whatever they think will defeat the trap. And die.

The solution is to just walk through the door. Anyone who is supposed to be there already knows that.

So when you lay out a trap, don’t do it randomly. Don’t put a trap there just to be a challenge to beat or to whittle away your player’s supplies or health. Think about why the enemy force the PCs are dealing with, be it an enemy patrol or an ancient civilization protecting their tombs, would have laid a trap. Why there, and to what purpose? Kill or capture? Area denial? Test of Worth?

Why trap that location? And then devise a trap that makes sense, not just some silly puzzle that gives them a papercut.

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