dnd traps

The Complete Guide to DnD Traps

A Complete Guide to Traps for Dungeons and Dragons 5e

Traps are a classic cornerstone of Dungeons and Dragons. We’re all familiar with spike pits, rolling boulders, or swinging blades. These examples help highlight one of the best things about  DnD traps: they have a huge amount of variety! If you want to add some flavor to your dungeon, traps can provide a unique bit of spice.

With all their variety and a near endless amount of ideas you also get an near endless amount of effects, damage tables, and rules to know. This article is designed to help you over that hurdle and lay out a mental framework that you can use when designing or implementing traps in your game.

What Is a Trap?

Sometimes it’s better to give an example rather than an explanation. You can see a fantastic and truly classic trap in use here.

See! Wasn’t that great?

While it’s a bit silly, it illustrates the core elements of a trap. You start with misdirection: adding a surprise where players expect things to be normal. You follow this with a trigger that leads to the trap’s effect. Once triggered, the trap is sprung to either success or failure.

In almost every case in DnD a trap will follow those three steps: misdirection, trigger, effect. Each step has a chance for the players to escape. They might not be fooled by the misdirection, a player might disable a trap’s trigger, or a player may deftly dodge out of the way.

As long as you’ve gathered these core elements, you have a trap. It doesn’t matter if it’s magical, mechanical, or just a pit full of crocodiles. Traps can be simple or complex, but at their core they all have the same basic ideas running them.

It’s also important to note that each step of a trap gives players a chance to overcome the particular trap in a different way. This is what makes a trap both fun and interactive. We’ll be looking at perception, skill checks, or saving throws, each offering players a route of escape. Without these it’s not a trap, but instead an unavoidable, unfortunate event.

If a player perceives something is up in the first part of a trap they are able to circumvent it altogether. If they have the skills necessary to overcome a trap’s trigger they might be able to get away. If they’re not observant or skillful enough they can always fall back to a saving throw. Because they have a chance to escape each time the trap feels fair and the player gets to have a sense of control over their character’s destiny. Make sure players get these opportunities.

Why Use Traps in DnD?

Some people complain that traps suck. They might think they’re unfair or not fun. While that can be the case for some trap designs or traps that are used improperly, this generalization shouldn’t be applied to all traps. Traps have many uses in game and are a critical tool in the game master’s toolkit.

The main reason a dungeon master might want to use traps is their flexibility. As we discussed earlier, a trap has three core parts and each of those parts gives players different opportunities to interact with the game world. When a DM places a trap in a dungeon they’re making something for the players to overcome with different solutions and outcomes.

Best of all, every player approaches and interacts with traps differently. As a DM you might see players skillfully avoid your traps or blindly fumble their way through them. Each scenario can easily change the course of the session and no group of adventures will come out of a dungeon with the same story.

Beyond their flexibility, traps are often used to create narrative space in a game. While combat and role play scenarios are highly demanding of a dungeon master, traps require very little of the DM. When used skillfully, they can break up a session and help control pacing.

If players are aware of traps or the possibility pf them, they may spend more time discussing, observing, or asking questions about their surroundings. In this way traps serve a lot of meta game purposes and might help your players better imagine and experience the descriptions you’ve given.

What’s The Difference Between Traps and Puzzles?

Traps and puzzles are often conflated in dungeons and dragons. This happens simply by virtue of them often being used in conjunction. While it’s true they can be combined into one larger creation, a trap consists of the three core components discussed earlier where a puzzle is a mental challenge that must be overcome. In almost every case puzzles represent Intelligence locks in DnD. Solve the puzzle, receive a prize! This might be opening a chest or a door, clearing a path, or even making new information accessible.

Puzzles on their own are only about testing logic and understanding of a mechanic, whereas traps routinely get involved as a training mechanism. What this means is that the trap effect is the punishment for doing something wrong, while a puzzle forces them to learn the puzzle’s mechanics and restricts them from brute forcing the solution. This isn’t technically a trap since it is often missing that first core element of traps: misdirection. At best, this only serves to act as a trap once and then it’s just punishment every time after that.

While traps and puzzles can be used hand in hand, it’s important to recognize that they are separate things and usually have separate goals. Puzzles are there to be solved, traps are to be avoided. Puzzles are a test, where traps are a deterrent.

How to Use Traps in Your Game

So you know what a trap is, but how do you use traps in your game? They must have rules, right?

Well, that’s where things get complicated. Because traps can come in so many different shapes and sizes there is no definitive rule set for each type of trap. Instead, what Dungeons and Dragons provides is a rule framework that fits each piece of a trap. These rules are broken into a few discrete chunks around detecting, triggering, and disabling traps and then again around trap effects for damage, saving throws, and lasting effects.

Outside of these loose rules there is little official guidance on the use of traps, so we’ll seek to fill in the gaps for how to best set up, describe, and utilize traps in your game.

Trap Setup and Trap Descriptions

When placing a trap into your game you’ll need to figure out what it does, where it’s placed, and how it’s described. This can be as simple as a pit trap with a cover that collapses when stepped on or as complex as a magical trap that teleports a player into a room full of bees. In either case, your first priority is considering where the trap goes and describing that location.

Why is the description so important?

Without a description, your players have no knowledge of what to inspect or what they can interact with. Because of the nature of DnD, you’ll have to provide ample description of a location to allow your players to navigate the scene effectively. This is the case with all descriptions you give in DnD, but for locations that are trapped it becomes especially important.

You still don’t want to describe the trap itself in any great detail, because it’s not supposed to be seen. However, the trap’s elements should be described so that players have a chance to inspect them. If your trap involves exploding statues, make sure you describe the statues so your players know they’re in the room and can be examined.

Failing to give a trap’s location an adequate description will most likely result in your players feeling cheated. If they didn’t know the room was made of stone tiled flooring, they wouldn’t have known to check for pressure plates. This kind of misstep is what leads to people complaining that traps are unfair and not fun, but it’s easy to avoid if you give your players good descriptions of an area and plenty of chances to interact with the scene.

The last piece of information necessary when describing a scene is misdirection. It has to either go undetected or be triggered carelessly. A description of a trapped location cannot only focus on the trapped elements. If a room has a trap in it you should paint a full scene and describe the mundane features as well as the dangerous ones. This defies the storytelling principle of Chekhov’s Gun, but that’s okay here because the story is still being written and someone checking out the wrong thing could end up being what causes them to discover the trap.

Triggers

Triggers for DnD traps come in two distinct types: mechanical and magical. Mechanical traps are your everyday mundane triggers. These can be things like pressure plates, trip wires, or even simpler things like breakaway flooring. All of the mechanical traps require physical interaction of some kind to work.

Magical traps use magic for the trigger. Magic in these kinds of traps acts as a sensor and allows the trap to trigger based on non-physical interaction. For example, a player enters a warded area or a certain number of people are in a room. The magical traps are ones that allow for advanced conditions to be triggered.

Mechanical Triggers in Use

Mechanical triggers need physical interaction, which makes their placement and activation path very straightforward. If you’re using a pressure plate, it needs to be where someone would step on it. While these might seem to be the simpler traps, they are also much harder to specifically set off due to their specific triggering requirements. Some common mechanical triggers include:

  • Pressure plates
  • Trip wires
  • False floors
  • Push buttons
  • Levers
  • False keyholes
  • Door knobs
  • Weakened supports/balance beams
  • Snares
  • Glue

Magical Triggers in Use

Magical triggers serve two important purposes for traps. First, they allow you to use non-mechanical means to set off a trap. Second, they allow traps to have more complex conditions. This could be a logical process or simple check list. While typical arcane triggers would be things like a glyph of warding or arcane ear, once you introduce the concept that a trap is magical it could follow any rules you want. Some examples of magical trigger conditions are:

  • Something is read
  • Something is said
  • A person enters an area
  • Multiple people enter an area
  • Someone casts a spell in an area
  • A particular race or creature enters an area
  • A player leaves an area
  • Noise gets above a certain level
  • The presence of water/light/air etc.
  • Line of sight with an arcane eye

As you can see, magical traps come in a variety of forms. The triggers can be made to meet just about any condition you want. With all this flexibility you can always make something work in your dungeon.

DnD Trap Effects – What happens when they go off

The real meat and potatoes of trap making is the effect. Most of the common traps you know of are named by what they do. This just goes to show you that the effect is the memorable part of any trap that you in your campaign.

Trap effects can be almost anything, but that doesn’t mean everything makes a good trap. The most common traps fall into three distinct effect types: alerting, trapping and killing. Alerting traps are those that set off alarms. Trapping effects are those that impede, stop, or restrain their target. Killing types do damage.

A simple pit trap is a trapping type while a spike pit is a killing type. It’s as easy as that. The reason you might want to think about this distinction comes down to why the trap was made. If the trap is set up outside a bandit camp, they most likely want to be alerted or they want to trap their target to ransom or extort them. In an ancient dungeon a trap might have been designed to protect ancient magic and would therefore fall into the killing type.

Rules for trap effects and their classifications are only focused on damage. Even though a trap can do a lot more than damage, the other effects are so numerous you can’t really write up rules for everything. When it comes to trap damage, the SRD defines it in three categories, each with their own save DC and attack bonus. These groups are termed: Setback, Dangerous, and Deadly. The table below shows their save DC and attack bonus.

Trap LevelSave DCAttack Bonus
Setback10–11+3 to +5
Dangerous12–15+6 to +8
Deadly16–20+9 to +12

Next we would look at damage severity by level.

Character LevelSetbackDangerousDeadly
1st–4th1d102d104d10
5th–10th2d104d1010d10
11th–16th4d1010d1018d10
17th–20th10d1018d1024d10

As you can see, traps can scale quite a bit over the course of a game. What’s considered deadly at level 4 is a setback at level 11.

Even though the rules don’t provide much context for traps outside of damage, you can have many non-damaging effects like locking people in rooms, poisoning them, casting any number of spells on them. The sky’s the limit when it comes to trap effects, so don’t feel boxed in when you’re setting them up.

Trap Effects and Player Actions

Players who hate traps usually find themselves being hit by something when it’s too late to react, which causes a trap to lose that fun interaction bit. Even though a trap has gone off successfully and the players had ample time to detect and disarm it, from their perspective they had no clue something was about to happen. This is a common problem and one that can be overcome with a simple question:

“You hear a click – What do you do?”

Just by asking a player how they react in that instant gives them back that bit of agency that they might have been missing. Likely they will still take damage from a trap, but by having the opportunity to react they’ll feel like they have a chance. When a trap goes off and you describe its effects, always give your players that one last out. If they come up with a creative solution or a good response, reward them with advantage or a bonus on their save.

Trap Detection

“I search for traps!”

As a DM you’ve likely heard your players shout this out more than a few times, but what does that actually mean? In the most basic context of the rules, searching for traps is a check of a character’s active or passive perception against the trap’s DC to be detected. A well-hidden trap will have a higher DC and require active perception rolls to spot, where a hastily made trap might be obvious and get spotted with passive perception.

If you want trap detection to be as painless as possible and you want your players to have fun, always use their passive perception. As veteran adventurers they are always looking for traps passively. It’s in their nature. If you explain this to your players they won’t shout “I search for traps!” every time they enter a room.

Beyond this, make sure you don’t automatically set your trap DCs above their passive perception. Some traps will be easy to spot for them, and that’s fine. The point of a trap is provide a challenge for your players to overcome, not to arbitrarily punish them for playing the game.

When a player does try to spot traps actively, ask them what they’re looking for. If they mention something that would be part of the trap, give them a secret bonus (or advantage) to their roll or lower the trap’s DC. This rewards them for active participation and thinking. Don’t do the opposite and punish them for not guessing the right spot; in those cases, just leave the DC for the trap as is.

As a refresher, passive perception is calculated as 10 + the wisdom modifier + proficiency if applicable.

If a character has advantage on a passive check for whatever reason, you add 5 to the skill check. This goes for passive perception as well.

Detecting Magical Traps

In addition to the normal ways that one can spot traps, magical traps can also be discovered by the Detect Magic spell. Higher level magical traps may be shielded from this kind of detection, but for the most part Detect Magic should be allowed to look for traps.

Interestingly, Detect Magic does not reveal that something is a trap, only that is is magical, where it is, and what type of magic it is. Magical traps are typically from Abjuration (glyph of warding) or Divination (arcane eye) schools of magic. If the trap sets off spells when triggered then the type of magic is the same as the spell that would be cast.

Disabling Traps and Overcoming Obstacles

Once your players have detected a trap they may want to disable it. This is not always a simple affair and can lead to them setting the trap off anyway. When describing a trap that can be disabled there will most likely be a DC for disabling it. To get an approximate sense for how difficult it would be to disable a trap, we can refer to the SRD’s table of task difficulty, reproduced below.

Task DifficultyDC
Typical DCs for Skill Checks
Very easy5
Easy10
Medium15
Hard20
Very hard25
Nearly impossible30

For most mechanical traps the DC is the Dexterity check needed to disarm the trap with thieves tools or a a similar kit. Attempting to disarm a trap without the necessary tools should be rolled at disadvantage. Depending on the trap, a failed ability check here will set the trap off.

If disabling magical traps, a caster could use Dispel Magic, where the DC is provided by the trap description. While not explicitly stated in the rules, a player could attempt an arcana check to see if there are other ways to disable a magical trap. This kind of leeway makes interacting with traps more accessible to the group and helps keep them from burning spell slots on a trap-heavy dungeon.

Circumventing DnD Traps

The other way traps are “disabled” is for them to go off without effect. Your players may see a dart trap and plug up the holes or raise a shield to them. These are great solutions to the problem and players shouldn’t be punished for trying things out.

When circumventing a trap’s effect, players will get creative and as a DM you’ll need to get equally creative in how this affects the outcome. Traps are almost always specific in their design. What this means is that there are lots of different ways to overcome and bypass a trap in most designs.

While a trap bypass can be intended by the designer, like with a trapped chest, it might also be unintentional, like a spike trap with gaps between the spikes. Give your players room to experiment. As long as their ideas aren’t fool hardy, you should let them get away with trying creative solutions to these problems.

How to Make DnD Traps

Often people have trouble coming up with new and exciting traps. Traps can be great, but they get stale when you don’t introduce new ones. This is why a simple framework for creating and thinking about traps can be useful. What follows below will be a simple outline for creating your own traps and keeping them from getting stale.

Planning

This is the most important step for almost everything. When it comes to traps, planning is about placement, theme, and intention. Consider the session as a whole and think about who placed the trap and why it was placed. If the trap is a deterrent, it might not be deadly. If the trap is guarding something super powerful it might be designed in a way that would simply kill the average person (player characters are not the average person).

Another important part of planning are your thematic elements. A wizard’s lair will have more magical traps while a forest might have snares and pit traps. The location and session story can help you design better fitting and unique experiences for your players. In some cases even monsters will set odd traps specific to themselves, like the Ettercap does.

Add a Trigger

Once you have your location and theme in mind you’ll need to pick a trigger. Choose its type first, mechanical or magical, before deciding the specifics. The actual trigger itself should be chosen so that it is a likely to be set off for those who don’t know the trap is there, but still easily avoidable for the trap maker or individuals who are aware of its presence.

Add an Effect

There is no limit on what an effect can do, so how do you choose a good one? There are two simple rules of thumb that you should be following. First, look back at your planning and match your effect to the theme or session in some way. A water temple might try to drown people.

Second, you want to make sure the trap effect is interactive in some way for your players. This means scaling it so that it won’t kill anyone at full health outright. This gives players a chance to deal with the aftermath and generally have some sort of lasting mini consequence. A pit trap is great because even after the trap is sprung, players need to figure out how to get out of it.

Similarly, most trap effects present something for the players to look out for or overcome in future parts of the scenario. This way failing to notice a trap is a teaching moment and not just a one-off disappointment.

Write a Description

You’ve got your components, now you need to describe it. In this step you should walk through each part of the trap as it happens. Be concise, but detailed enough to clearly explain what happens. A good description walks the players though the sequence of events that leads to the effect and then describes the effect in full. The main reason for doing this exercise is so that your players understand, from a story point of view, exactly what happened and are not confused about the damage they just took.

It is easy to be lazy with this and say something like “A torrent of fire erupts from the statues mouth, make a Dex saving throw,” but this does not clearly explain that a trap has been triggered. Going through a scene for a trap should start with the action that precedes the effect, some cue that the trap is sprung, the players reaction (what do you do?), and then the full effect description. This gives the players enough information to interact with the scenario and in general makes for better use of traps.

Add in the Math

Math and rules come last. Why? Because it’s hard to slot them in piecemeal. If you add the math too early, you may spend more time going back and adjusting it. For this step, refer to the tables above for trap difficulty and DCs for average skill checks and assign them to be appropriate for your players level. It is a little weird that traps would scale with your players, but that’s just the way the game needs to go sometimes.

When adding in damage, remember that the output should never be enough to kill a player in your group at full health. In no case should a trap ever reduce a character to a red mist. Always give them a chance to recover or overcome. Things that can kill a player outright need to be obvious. If you want a trap to be exceedingly deadly, make it detectable with passive perception so that your players know the risk before interacting with it.

When setting your DC to disable a trap, be sure to set it based on the scenario. If a trap can easily be bypassed, you can set the disarm DC much higher than you would for a trap that blocks a critical path for the story.

Sample DnD Traps

We’ve got a ton of sample DnD traps for you here at Master the Dungeon. You can find them here in the Trap Tuesday section of the blog. We release new DnD traps for you almost every Tuesday. There are plenty of ideas for you to dive into already and simple guides on how to use different types of traps effectively.

Now that you know everything you need to about traps for 5th edition Dungeons and Dragons, go out and surprise your party!

Happy DMing!