Reconceptualizing Traps in Dungeons and Dragons 5e

A pretty common issue I see in encounter design, both in official and un-official sources is a severe lack of understanding that a trap is an encounter. Using a trap as a momentary gotcha is not nearly as interesting as creating a compelling problem for the party to solve, so how do we go about doing this?

Before we can go about making traps better, we need to start by understanding how they commonly get misused. Does this sound familiar? A character either rolls or notices a trap through perception/passive perception. This character or another may investigate to figure out the specifics of the trap. This character or another may make a dexterity check to disable the trap. There are clear success and failure states, the party may or may not use up some resources or worse, but nothing very interesting happened. A few dice were rolled, sure, but where was the encounter? What decisions were made other than ‘I check for traps, I ask for an explanation of the trap, and I attempt to disable the trap?’

Let’s take the above scenario and look at what success and failure states of the above look like.

  • Perception Check
    • Success – The party has noticed that a trap exists!
    • Failure – The party is unaware of the trap and probably sets it off.
  • Investigation Check
    • Success – The party has identified the solution to the trap!
    • Failure – The party isn’t sure how the trap works. They may decide to press forward and intentionally trigger it or retreat to find a way around it.
  • Dexterity Check
    • Success – The party has disabled the trap and can move forward with their goal!
    • Failure – The party will suffer the consequences of the trap.

Now, there is a lot of good advice on traps in the documentation for 5e. Specifically there are notes about not allowing rolls to supersede clever play, with a specific example that looks like this.

“Consider a trapped Treasure chest. If the chest is opened without first pulling on the two handles set in its sides, a mechanism inside fires a hail of poison needles toward anyone in front of it. After inspecting the chest and making a few checks, the Characters are still unsure if it’s trapped. Rather than simply open the chest, they prop a Shield in front of it and push the chest open at a distance with an iron rod. In this case, the trap still triggers, but the hail of needles fires harmlessly into the Shield."

That’s good advice; this is treating a trap like part of the world! In order to build better traps, this needs to be our bare minimum expectation of play. So how can we set players up to do this with simple traps?

Step one is to be explicit about what they found. Like the above example, the characters have found a treasure chest that they expect to be trapped. If they succeed on their Investigation check, they know how the trap operates. An incomplete success may let them know that there are small holes in the front of the chest, but not how to disable it. The players can then decide how they want to proceed. Now those holes could have needles, or could let out poison gas, or could be a diversion from the actual trap. Good design on your part means you know what they are and how likely the player’s actions are to succeed. In the case that failure or success is assured, no dice need to be rolled, simply apply the effects of the action.

Now, not all traps need to be this simple. A trap that goes off without serious consequences is hardly worth considering for adventuring parties. It would have been nice not to lose some hp but at the end of the day it’s unlikely to be the difference between success and failure. Killing a player character outright for a bad check is a bit of a harsh trap for many (though not all, of course!) adventures, so we need to figure out how to create tension in the encounter without a simple, instantaneous effect. That means that we can treat this way more like combat. A series of decisions can add up and leave the characters victorious or in dire straits.

There are some very good examples of this type of design in popular D&D media, for example Matt Mercer’s acid room in Campaign One, episode 34 of Critical Role. The acid trap as written had the potential to TPK a party that was unprepared for it, though the solution used wasn’t remarkably complicated. There was tension in the scene because the trap created a time constraint, the scene involved a betrayal and a spell that dominated an additional party member, a grave mistake was made by a player, and the party could not afford to waste many resources given what they would face after. The final solution was simple, the characters just needed to break a series of objects to get the trap open with one of them being outside the room they were trapped in. They took a considerable amount of time; so Matt made this a partial success (the trap mechanism was damaged by acid,) and forced the party to find a way to disable the part of the trap that allowed acid to continue to flow. Had the party failed to disable the trap it was unlikely that many of them would have survived, nor would the survivors have been in a position to continue their mission.

If you’re looking to create similarly interesting traps you’re going to need similar design goals for the encounter. Because the trap required the characters to use multiple spells and limited use objects searching for a solution without the hope of resting on the other side, it was reasonably useful for creating a challenge that was meaningful in the final outcome of this adventure arc. Here’s the bigger concept laid out simply:

A challenging trap

  • forces multiple party members to use valuable resources
  • depletes hit points
  • creates a time constraint
  • allows room for creative solutions
  • has an option for partial success and failure on individual success
  • carries real risk for the party

I’ll provide an example trap for a lich’s lair. This is an interesting trap to design because a lich is aware that a party coming to the lair is either stupid, overly reckless, or feels they are clever enough to avoid a trap. In order to manipulate the party he would really fear, he’s going to setup some simple, obvious traps as they move along. Tripwires with swinging blades, heated floors, etc. Things that a party can easily disable without much effort or resource loss. As they push further in they’ll find another trap that looks something like this.
With a successful Wisdom (Perception) check of DC10.

A huge, empty room stands before you, with a glyph in the middle of the floor about 300' from the entrance. Torches line the walls, flickering in a breeze you can't feel. A matching glyph is centered above on the ceiling.

A slightly higher DC would indicate additionally:

A series of small holes lines both floor and ceiling.

This trap seems simple and relatively obvious. The party will probably assume the glyph is magic and will cause the room to be filled with flying needles or make a flame blast go off. The cues are there and relatively clear. However, there is more to this trap than meets the eye. Parties that attempt to use an Intelligence (Arcana) check with a DC15 from outside the room will receive the following information.

The glyphs on the floor and ceiling in the center of the room are powerfully magical. Disabling the glyph on the floor will disable the trap connected to it.

A very cautious party is going to have a different experience from a reckless party. If a single character enters the room, nothing happens until the character is 20’ from the door. At that point, a stone slab falls from the ceiling in front of the entry to the room. An alarm, silent or otherwise, goes off and leaves the party on the outside dealing with a wave of minions in the corridor. The party member stuck inside the room will quickly realize that there is no air in the room and will have to figure out how to deal with that situation. On both sides of this encounter it’s reasonably likely that the party is going to have to expend significant resources, or even lose a party member. They’re considerably weaker moving forward! Even once they deal with the current issue they’re going to have to deal with the glyphs to pass the room, which brings us to the reckless party.

The reckless party has a slightly different experience. As the party walks into the room something strange happens. The room itself is on a tumbling pivot, unlikely to be set off by just a single player character. It tumbles multiple times, subjecting the characters to minor fall damage but, more importantly, bouncing them off the glyphs. Symbol spells go off from each glyph, but the doorway remains open and allows them to continue deeper into the lair. The meatheads lose some hit points, are delayed in their approach, and become a little riper for harvesting.

One of the interesting things about this specific trap is that it allows a party that isn’t interested in engaging with the trap in a serious way to just bypass it with a minor tax on a relatively simple resource. It communicates the flavor of a trick, mean-spirited, undead wizard either way; but the party that the lich would fear is going to have a more interesting encounter and be weaker on the other side. It makes sense from a logical, world building perspective, and allows for some fun gameplay!

I’ll have more thoughts about this in a future post, but I think that’s enough to chew on for the moment!

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