D&D 5E Traps and DCs

[slaughterj]

Passive perception can be use for every ambush or no ambush, ever trap or no trap, or you can use like Iserith suggested and allow it when the player says something that would indicate passive perception is warranted. As for how I would determine the ambush, I'd roll once with whatever bonus orcs get. Look at combat. You don't roll initiative for all 4 orcs, so why would you roll stealth individually?

Flip the script. You have all the PCs roll for stealth individually though don't you? You have all the PCs roll for initiative individually don't you? Initiative is done in groups of bad guys for a gaming shortcut.

 

[slaughterj]

If the trap is imminent, similar to an ambush, I don't think there's any problem getting the PCs to roll active perception checks on the spot. If they make it, they spot the trap, well and good, if they fail, the trap goes off - move onto what happens next.

I agree PP vs static trap DC doesn't work, which is why I suggest just roll all the time and forget PP. But your idea of rolling the DC for the trap also works.

If you're worried about "tipping off" the player to a non-imminent trap, roll it secretly for him or get players to roll before the session, make a list of 10 rolls, and go down the list. Or backwards up the list. Or middle outwards. However you want to do it while keeping players in the dark.

The need for this this kind of secrecy though is extremely limited in my experience. Big set piece (what some might call "quality") traps tend to be telegraphed first, and then interacted with in a complex way. Simple resource attrition traps happen immediately, and so an active perception check in the open doesn't cause any issues, similar to an imminent ambush.

But then you have the issue of how many PCs get to roll and many of them potentially getting a roll and the issues with variances that you get with a lot of rolls, versus avoiding that problem and the simplicity of a single roll for the trap. Also, just because you fail to perceive the trap, does not mean it goes off automatically, though for many simple traps, that would be the case, but there are others that take time (think of the boulder in Indiana Jones) or require just a bit further PC action to actually trigger (PC moved up the hall to the point of stepping on the pressure plate, failed the roll, but hasn't moved further, and moving further is what causes it to go off, like a land mine).

 

[jgsugden]

In my games, I've used the same system since the late 90s - ever since the first time I heard of the passive perception concept (under a different name, then). There are three rolls for every trap or hazzard: Notice, Understand and Disable. It isn't Rules as Written, but it is just a slight variation on the current rules.

Notice: Passive Perception only gives you the full reveal if you beat the DC by 5. If not, all you get from passive is a hint that something is off. Then a perception roll is required to get the real details of what you're observing. However, all you get are the surface facts - not an understanding of what might be going on outside of what you can directly observe/hear/etc... Sometimes an active roll that fails by too much might set it off.

Understand: Once you have perceived there is something dangerous, you have to do a separate roll to understand how the trap works. This can be arcana, investigation, sleight of hand, thieves tools or some other skill depending upon the trap. Failing by too much sets it off.

Disarm: Then you need to disable it on a third roll. This is often sleight of hand or thieves tools, but could also be arcana, etc... and failing by too much sets it off.

The three DCs will differ from situation to situation. Some might be hard to find (DC 20 perception), easy to understand (DC 12 investigation (set off if you don't get at least a 7)) and difficult to disarm (DC 18 sleight of hand/thieves tools, under 13 sets it off). Others could be easy to find (Perception 5), Impossible to understand (arcana 22, under 15 sets it off), and easy to deactivate (12 arcana to disable, under 10 sets it off).

If the PCs come up with a good reason why a particular skill could be used to understand and/or disable a trap, I just come up with an extra DC on the spot.

This has served me well.

 

[iserith]

In my games, I've used the same system since the late 90s - ever since the first time I heard of the passive perception concept (under a different name, then). There are three rolls for every trap or hazzard: Notice, Understand and Disable. It isn't Rules as Written, but it is just a slight variation on the current rules.

Notice: Passive Perception only gives you the full reveal if you beat the DC by 5. If not, all you get from passive is a hint that something is off. Then a perception roll is required to get the real details of what you're observing. However, all you get are the surface facts - not an understanding of what might be going on outside of what you can directly observe/hear/etc... Sometimes an active roll that fails by too much might set it off.

Understand: Once you have perceived there is something dangerous, you have to do a separate roll to understand how the trap works. This can be arcana, investigation, sleight of hand, thieves tools or some other skill depending upon the trap. Failing by too much sets it off.

Disarm: Then you need to disable it on a third roll. This is often sleight of hand or thieves tools, but could also be arcana, etc... and failing by too much sets it off.

The three DCs will differ from situation to situation. Some might be hard to find (DC 20 perception), easy to understand (DC 12 investigation (set off if you don't get at least a 7)) and difficult to disarm (DC 18 sleight of hand/thieves tools, under 13 sets it off). Others could be easy to find (Perception 5), Impossible to understand (arcana 22, under 15 sets it off), and easy to deactivate (12 arcana to disable, under 10 sets it off).

If the PCs come up with a good reason why a particular skill could be used to understand and/or disable a trap, I just come up with an extra DC on the spot.

This has served me well.

Is there always a roll to notice, understand, or disarm a trap regardless of what the players describe their character as doing?

 

[jgsugden]

Is there always a roll to notice, understand, or disarm a trap regardless of what the players describe their character as doing?

Always? Ehhh... I can't say that. For example, I might decide that the trap is totally obvious and I know the PCs have a high passive perception, so there is no roll to notice considered. They may also come up with a solution that gets them past a trap without needing to disarm it. Like everything in D&D, the general rules are pushed aside when the best stroy is achieved through other means.

The way I view dice and declared actions works into this a bit: Dice are rolled for things outside the control of the PC. Players tell me what the PC is trying to do. If they wish to attempt something and I think there should be a chance that it fails, I ask them to roll dice. If there is no reasonable chance what they declare would not work, no dice are rolled - even if this violates the RAW.

Traps, by their nature, are intended to be difficult to address. As such, generally, they are hidden, have elements that are hard to understand, and they are difficult to counteract. As such, there is generally a chance to fail each element. As such, strongly tend to be involved. However, some traps should be trivial to spot, to understand or to disarm - meaning I might bypass the roll if I feel the roll serves no purpose.

 

[Maxperson]

Flip the script. You have all the PCs roll for stealth individually though don't you? You have all the PCs roll for initiative individually don't you? Initiative is done in groups of bad guys for a gaming shortcut.

Of course PCs roll separately. Why? Because it's more fun for the each player to roll his own dice and because there is only one each. The DM is controlling many more creatures and paying attention to many other details. I don't have the time or inclination roll initiative or stealth checks for sometimes upwards of 50 creatures.

The two sides are different, so that one side rolls individually has no bearing on whether the other side does, or even should roll individually.

 

[slaughterj]

Of course PCs roll separately. Why? Because it's more fun for the each player to roll his own dice and because there is only one each. The DM is controlling many more creatures and paying attention to many other details. I don't have the time or inclination roll initiative or stealth checks for sometimes upwards of 50 creatures.

The two sides are different, so that one side rolls individually has no bearing on whether the other side does, or even should roll individually.

Yes, and just because you choose to roll the Orcs' initiative as a group has no bearing on whether you should do a single roll for their perception as a group, initiative and perception are two different activities with different significances.

 

[slaughterj]

In my games, I've used the same system since the late 90s - ever since the first time I heard of the passive perception concept (under a different name, then). There are three rolls for every trap or hazzard: Notice, Understand and Disable. It isn't Rules as Written, but it is just a slight variation on the current rules.

Notice: Passive Perception only gives you the full reveal if you beat the DC by 5. If not, all you get from passive is a hint that something is off. Then a perception roll is required to get the real details of what you're observing. However, all you get are the surface facts - not an understanding of what might be going on outside of what you can directly observe/hear/etc... Sometimes an active roll that fails by too much might set it off.

Understand: Once you have perceived there is something dangerous, you have to do a separate roll to understand how the trap works. This can be arcana, investigation, sleight of hand, thieves tools or some other skill depending upon the trap. Failing by too much sets it off.

Disarm: Then you need to disable it on a third roll. This is often sleight of hand or thieves tools, but could also be arcana, etc... and failing by too much sets it off.

The three DCs will differ from situation to situation. Some might be hard to find (DC 20 perception), easy to understand (DC 12 investigation (set off if you don't get at least a 7)) and difficult to disarm (DC 18 sleight of hand/thieves tools, under 13 sets it off). Others could be easy to find (Perception 5), Impossible to understand (arcana 22, under 15 sets it off), and easy to deactivate (12 arcana to disable, under 10 sets it off).

If the PCs come up with a good reason why a particular skill could be used to understand and/or disable a trap, I just come up with an extra DC on the spot.

This has served me well.

That is an interesting approach, thanks for posting.

 

[Maxperson]

Yes, and just because you choose to roll the Orcs' initiative as a group has no bearing on whether you should do a single roll for their perception as a group, initiative and perception are two different activities with different significances.

You don't appear to know what you are talking about. The same reason for rolling initiative as a group applies to all rolls for that group other than actual combat rolls like attacks and saves. It's too time consuming for the DM, and just plain boring for the players. They don't want to wait while I roll 50 times to see if the orcs detect the PCs sneaking up on them.

 

[Rya.Reisender]

Nothing weird at all, and no reason to assume so. Here's a concrete example. The party is advancing through the dungeon. The scout spots signs of a trap ahead. Further ahead, they hear an advancing monster patrol. The party wants to try to disable or circumvent the trap fast enough to get past it and slip into a side room ahead and avoid being noticed by the approaching patrol. See, that wasn't very hard or weird.

Wait, you start this example already with the traps and the advancing monster patrols noticed and I assume that's from their passive perception, so where does that consume an action? If the monster patrol spotted them already you would already be in combat mode, then of course actions do matter. If a player then says he wants to disarm or circumvent the trap, then of course that would require a turn. But that's completely unrelated to passive checks.

I did not say I would like to use active checks. I simply noted issues with using them. While there may be less of an issue for surprise with active checks (assuming you circumvent the issue of too many active Perception rolls making Stealthy by ambushers practically impossible), as presumably the ambushers would then begin the surprise round, it does in fact work differently for traps. If a PC is asked to make a Perception roll while strolling down the dungeon hall, and rolls low, the PC may well be alerted to a potential issue and change his tactics to be more cautious, to start probing the floor with a 10' pole, etc. So it does have a potential for an impact to call for an active Perception roll.

Don't really see an issue with that either. If a PC checks for something and rolls low peception, then you can just tell him he doesn't find anything. That he is then hesitant is okay. If you check for something and the outcome is that you are unsure, then acting unsure makes sense.

By the way, what exactly are the issues with active checks you are referring to? You mean the ones we are discussing right now, that they take an action and give PCs meta information? Because I see neither as issue... can you elaborate?

But here's the problem with that, which I raised in the initial post and several times since. If passive Perception is good enough, then PCs will simply auto-find simple traps, making them ineffective, boring, a waste of time, etc. Look back at what I originally wrote.

As I told you before. If the PCs have enough passive perception don't just tell them "There's a trap", instead describe aspects of the trap that they notice, let them conclude there is a trap themselves. Then it's much less boring.