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Poison needle traps

Wyvern

Villager
I recently read a DMs Guild adventure that included a poison needle trap, and I found the wording ambiguous. At first I assumed it was the author's poor choice of wording, but I later found that it was mostly a copy-and-paste from the trap rules in the SRD:

A poisoned needle is hidden within a treasure chest’s lock, or in something else that a creature might open. Opening the chest without the proper key causes the needle to spring out, delivering a dose of poison.

When the trap is triggered, the needle extends 3 inches straight out from the lock. A creature within range takes 1 piercing damage and 11 (2d10) poison damage, and must succeed on a DC 15 Constitution saving throw or be poisoned for 1 hour.

A successful DC 20 Intelligence (Investigation) check allows a character to deduce the trap’s presence from alterations made to the lock to accommodate the needle. A successful DC 15 Dexterity check using thieves’ tools disarms the trap, removing the needle from the lock. Unsuccessfully attempting to pick the lock triggers the trap.
Here's my problem: the final line, "Unsuccessfully attempting to pick the lock triggers the trap," could be taken to mean that *successfully* attempting to pick the lock *doesn't* trigger it. But picking the lock would count as opening it without the proper key, and an unsuccessful attempt to pick the lock wouldn't allow it to be opened in any case. The only way I can think of to reconcile these two statements is that *any* attempt to pick the lock, successful or otherwise, will trigger the trap unless it's already been disarmed. Is that how other people interpret it?

Wyvern
 

Paul Farquhar

Explorer
It's up to the DM to decide what exactly triggers the trap.

Sometime even using the proper key will trigger the trap unless a secret switch is held down. Check out the suitcase in From Russia with Love.
 

Imaculata

Explorer
The wording seems pretty clear to me:

"Opening the chest without the proper key causes the needle to spring out"

Lockpicks are not the proper key. So yes, they cause the trap to spring, unless:

"A successful DC 20 Intelligence (Investigation) check allows a character to deduce the trap’s presence from alterations made to the lock to accommodate the needle. A successful DC 15 Dexterity check using thieves’ tools disarms the trap, removing the needle from the lock."

Note that the player must first declare an investigation action to notice the trap. Don't just tell them to make an investigation check, unless they specifically state that they are checking for traps. And failing the disarm-check obviously also springs the trap. Failing to pick the lock in the first place would probably also spring the trap, but that is up to the DM to decide. How sensitive is the trap?

Where these sort of traps usually fail, is that they don't take into account 'how' the player goes about opening the chest, or disarming the trap. If the player just uses a crowbar from the side, that needle is not going to do a thing, even if this does trigger the trap. Likewise, if the player decides to keep his hands away from the lock while trying to disarm the trap, and fails, then the needle shouldn't hit him.

Frankly I would design the trap in such a way that it either shoots a needle in 8 directions outward from the chest, or that it shoots a needle from inside the chest, upward at whoever opens it. Heck, maybe its not even a needle, but a cloud of gas that hits everyone in close proximity to the chest. Having the needle pop out of the lock is awfully specific, and very prone to miss its target.
 
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Shiroiken

Explorer
Note that the player must first declare an investigation action to notice the trap. Don't just tell them to make an investigation check, unless they specifically state that they are checking for traps.
Technically passive Investigation should be used here, if the DM uses passive checks.
 

Imaculata

Explorer
Technically passive Investigation should be used here, if the DM uses passive checks.
Would you passively notice a carefully hidden trap? I think an argument could be made that you should actively search for it. But I guess that is open to interpretation.
 

DEFCON 1

Hero
Here's the other way to look at it: It says "Opening the chest without the proper key"... the use of the word 'proper' is there not to indicate that this specific key is the only thing you can use to open the lock... but merely to distinguish that key from any other key you might use. You could take the word out and be left with 'Opening the chest without the key', or take it out and rephrase it longer as 'Opening the chest without the key designed to open that specific lock'... but they went with just using 'proper' to indicate the specific key for that specific lock.

So the phrase is there to distinguish one key from all the others, but it is not implying that the key, lock, and chest are somehow magical and that there's some sort of connection between them that makes the key the only thing that can open the lock. Instead, like all locks they can be picked.

If you don't use the proper key meant for the lock, then whatever other regular key you attempt to use will hit a couple incorrect tumblers (or some other internal lock mechanic bit) inside the lock which will trigger the needle trap. If you try and pick the lock and fail, you'll hit a couple incorrect tumblers (or some other internal lock mechanic bit) inside the lock as you are picking it which will trigger the needle trap. If you successfully pick the lock, then it means you never hit any incorrect tumblers (or some other internal lock mechanic bit) and thus unlocked it just as if you had the proper key.

Like the others above have said, the DM can rule it however they want. For me personally... needle lock traps are so basic that I just run them at the most basic level-- you stick anything into the lock that doesn't successfully unlock it... the needle gets sprung.
 

jasper

Explorer
The trap is triggered on the disarm attempt. If the thief misses the DC, he takes damage and rolls the con save. Generally I play if you miss the thieves tool attempt you take the damage.
 

Imaculata

Explorer
If you successfully pick the lock, then it means you never hit any incorrect tumblers (or some other internal lock mechanic bit) and thus unlocked it just as if you had the proper key.
It doesn't say that. It says that only the proper key will not trigger the trap.
Sure, you can pick the lock. But the description doesn't say that the trap won't trigger.

For that you'd either need to disarm the trap (A successful DC 15 Dexterity check), or use the proper key.

Look at it this way: The trap is designed to trigger if you don't use the key. Meaning that the fact that people might find some other way to open the chest is taken into account in the description. That's what the trap is there for: To hit people trying to open it without the key.
 

Li Shenron

Adventurer
A poisoned needle is hidden within a treasure chest’s lock, or in something else that a creature might open. Opening the chest without the proper key causes the needle to spring out, delivering a dose of poison.

When the trap is triggered, the needle extends 3 inches straight out from the lock. A creature within range takes 1 piercing damage and 11 (2d10) poison damage, and must succeed on a DC 15 Constitution saving throw or be poisoned for 1 hour.

A successful DC 20 Intelligence (Investigation) check allows a character to deduce the trap’s presence from alterations made to the lock to accommodate the needle. A successful DC 15 Dexterity check using thieves’ tools disarms the trap, removing the needle from the lock. Unsuccessfully attempting to pick the lock triggers the trap.
[MENTION=6801286]Imaculata[/MENTION], how can you say the wording is "pretty clear"? :)

It's not even clear whether the description here is for the trap only excluding the lock or if it is for trap and lock together.

(CASE 1)

If you assume the description is complete for the whole thing, then it sounds like you need only one check with thieves' tools for both disarming the trap and opening the lock, provided you first detect the trap. In this case the last sentence "Unsuccessfully attempting to pick the lock triggers the trap" suggests both checks are merged into one.

If you instead don't detect the traps (your Investigation fails or you didn't ever think about it), you automatically trigger the trap, before you finish your lockpicking. After that, since the trap doesn't reset, you can continue without further danger, but you still need to make the DC15 lockpicking check. In this case the last sentence "Unsuccessfully attempting to pick the lock triggers the trap" is irrelevant because the trap is already sprung.

An alternative interpretation would be to allow the character who is unaware of the trap to just lockpick, and not trigger the trap on a success. But then the benefit of a success at detecting the trap would be reduced to more knowledge before deciding whether to not lockpick at all to avoid the danger.

(CASE 2)

But what if instead the description is for the trap only? After all, the DC15 Dex check here mentions only disarm. So it's also possible to read the whole thing as not including the lock, and in fact there are different locks in the book with different DCs for picking them.

In such case, it takes two separate thieves' tools successful checks, one to disarm the trap and another to pick the lock.

If you detect the trap and decide to continue, you do first the disarm check. What happens on a failure? the description doesn't say if a failure in disarm triggers the trap or merely fails at disarming - not that other traps in the DMG specify what happens in this case, but not this trap! If you succeed, then you do the second check to pick the lock.

If you don't detect the trap, I still say it's more reasonable that picking the lock automatically triggers the trap.

As you can see, there are actually lots of options for the DM. The only fixed fact, is that the trap description is everything but pretty clear :)
 

iserith

Explorer
It just looks badly worded to me, perhaps an editing error, so it's up to you how it will ultimately function. It seems like the goal here is to set up a challenge of (1) finding the proper key or (2) disabling the trap then picking the lock. Anyone going straight to picking the lock is going to have a nasty surprise. That's how I'd handle it, anyway. I would also be sure to telegraph the existence of the trap in some way so that it isn't a "gotcha."

@Imaculata: A passive check does not imply that the character is being passive. "Passive" refers to their being no roll, not that the character isn't performing a task. In fact, the rules state that such checks resolve a character performing a task repeatedly. Whether the DM uses a passive Investigation check to resolve this situation depends on what, specifically, the player described the character as doing.
 

Wyvern

Villager
The wording seems pretty clear to me:

"Opening the chest without the proper key causes the needle to spring out"

Lockpicks are not the proper key. So yes, they cause the trap to spring, unless:
I suppose it's not *that* unclear, if you assume that picking the lock counts as opening it without the proper key. (As DEFCON 1 points out, you could make a case that picking a lock allows you to to "trick" the lock into "thinking" that the proper key is being used, but for the sake of argument I'll grant the point.) Even so, it's not as clear as it could be. Look at it this way: first we're told, in effect, that successfully picking the lock triggers the trap. Then, two paragraphs later, we're told that *unsuccessfully* picking the lock triggers the trap. (And none of this was helped by the fact that the adventure in question omits the words "without the proper key" and doesn't say anything about where the key can be found.)

If I'd been editing it, I would have changed it to "Attempting to pick the lock triggers the trap" (assuming that *is* the intended meaning), which is less ambiguous and more concise.


And failing the disarm-check obviously also springs the trap.
Only if failing to disarm a trap automatically sets it off as a general rule; the description of the needle trap doesn't say anything about whether that is the case or not. By contrast, the descriptions of the collapsing ceiling and falling net traps state that "On a failed check, the trap triggers." The fact that the description of the needle trap *doesn't* include this line could be taken to mean that a failed check to disarm the trap *doesn't* trigger it, or the omission could just be an oversight. In any case, it's not "obviously" true.

Failing to pick the lock in the first place would probably also spring the trap, but that is up to the DM to decide.
Of course the DM can decide whatever they like, but going by the RAW, it very clearly and unambiguously states that "Unsuccessfully attempting to pick the lock triggers the trap." No "probably" about it.


Where these sort of traps usually fail, is that they don't take into account 'how' the player goes about opening the chest, or disarming the trap. If the player just uses a crowbar from the side, that needle is not going to do a thing, even if this does trigger the trap. Likewise, if the player decides to keep his hands away from the lock while trying to disarm the trap, and fails, then the needle shouldn't hit him.
I don't view that as a failure; I view it as rewarding the players for using their brains. (Though I'm skeptical whether it's possible to remove the needle from the lock without putting your hands near the lock.)

Having the needle pop out of the lock is awfully specific, and very prone to miss its target.
Again, I consider that a feature, not a bug. In fact, I could argue that making the damage unavoidable if the trap is set off is a bit unfair; in 3rd edition, it would have made an attack roll to see if it hit you. However, that's an issue of design rather than wording. And since you can avoid the damage by wearing gauntlets, using a crowbar, etc., I'm not too upset about it.

As to the question of whether PCs can notice the trap without actively searching for it, I think that would depend on whether the needle springs from the keyhole itself or from another opening. If it's the latter, I would allow someone with sufficiently high passive Investigation to notice that there's an extra hole in the lock.

Wyvern
 

Wyvern

Villager
Here's the other way to look at it: It says "Opening the chest without the proper key"... the use of the word 'proper' is there not to indicate that this specific key is the only thing you can use to open the lock... but merely to distinguish that key from any other key you might use.... you stick anything into the lock that doesn't successfully unlock it... the needle gets sprung.
I agree with your reasoning; the only problem is that it doesn't jive with the statement that "Opening the chest without the proper key causes the needle to spring out." By definition, if you stick anything into the lock that doesn't unlock it, you haven't *opened* the chest. I suppose you could interpret it to mean that *attempting* to open the chest without the proper key triggers the trap, but that's not the wording they used.


The trap is triggered on the disarm attempt.
Except that it doesn't say that. RAW, there are two things that trigger the trap: "Opening the chest without the proper key," and "Unsuccessfully attempting to pick the lock." The sentence that describes how the trap can be disarmed notably does *not* say anything about the consequences of failure.

Wyvern
 

Satyrn

Villager
Here's my problem: the final line, "Unsuccessfully attempting to pick the lock triggers the trap," could be taken to mean that *successfully* attempting to pick the lock *doesn't* trigger it.
Without this line - "Unsuccessfully attempting to pick the lock triggers the trap" - the trap would only trigger when the chest is successfully picked, because up to this point we've only been told the trap triggers when opened without the right key.

So, I read this all as essentially saying "the trap is triggered when anything but the proper key is inserted into the lock."
 

Li Shenron

Adventurer
A passive check does not imply that the character is being passive. "Passive" refers to their being no roll, not that the character isn't performing a task. In fact, the rules state that such checks resolve a character performing a task repeatedly.
Despite the name "passive", I think you are right. The rule for passive perception was put there only to avoid cases when a players asks to do the same check 50 times, NOT to guarantee a minimum dice result of 10 (that's what Reliable Talent is for).
 

iserith

Explorer
Despite the name "passive", I think you are right. The rule for passive perception was put there only to avoid cases when a players asks to do the same check 50 times, NOT to guarantee a minimum dice result of 10 (that's what Reliable Talent is for).
As a tool for resolving an action declaration into a result, in my view it sits somewhere in between a task that is done a single time with an uncertain result and a task that can be performed repeatedly in such a way as to guarantee automatic success (DMG p. 237). So it's a task that can or must be performed repeatedly, but not one where performing it enough times will result in success. In general, I find that these are tasks that are performed when traveling, where "traveling" is defined as moving about in a dungeon or the wilderness and the tasks are often a trade-off against Keeping Watch (which is resolved with passive Perception).

I would likely not resolve this particular trap with passive Investigation, but again, it depends on a few factors not the least of which is what the player describes the character as doing.
 

DEFCON 1

Hero
Then I wonder if perhaps the final line is just written incorrectly in the description? Rather than saying that unsuccessfully picking the lock triggers the trap, the description was meant to say unsuccessfully disarming the trap triggers it? Seeing as how the sentence appears right after the bit about successfully disarming the trap?

That actually makes much more sense for both the bit that is missing (what happens if you don't successfully disarm the trap) and its placement in the description.

Change the sentence "Unsuccessfully attempting to pick the lock triggers the trap." to "Unsuccessfully attempting to disarm the trap triggers the trap." and everything appears to work fine.
 

Blue

Orcus on a bad day
Would you passively notice a carefully hidden trap? I think an argument could be made that you should actively search for it. But I guess that is open to interpretation.
For me, this is the poster child for when to use passive investigate. It's for something the character could notice, but when asking the player to make a check would tip them off.
 

Mistwell

Adventurer
The following things trigger the trap:

1) Attempting to disarm the trap and failing in your disarm attempt
2) Attempting to pick the lock of the trap and failing in your pick lock attempt
3) Opening the chest without first successfully disarming the trap

So yes, if you do #3, even after successfully picking the lock, it will go off. Of course, then it depends on how you opened the chest. You must be within 3 inches of the lock for it to harm you. You're going to be within 3 inches in #1 or #2. But you might not be within 3 inches for #3.

I've had players pick a lock on chest successfully, and then say they open it by jamming a dagger between the lid and the body of the chest from the side, while crouching down at the side of the chest. That would result in no harm from the trap being triggered.
 

Skyscraper

Villager
D&D 5E books have the following format for a power, trap or other game element. (see any class feature or monster description for example.)

1) give a general description of the game element.

For example, the description of the Barbarian's Reckless attack starts with "Starting at 2nd level, you can throw aside all concern for defense to attack with fierce desperation." This is not meant as a rule that the character is under obligation to throw aside all concern for defense or else he's banned from barbarianhood. It's just fluff.

For the poison needle trap, this description states "[o]pening the chest without the proper key causes the needle to spring out".

2) provide the mechanics of the game element.

For the Reckless attack, this essentially includes benefitting from advantage on Strength melee attacks while granting advantage to opponents, for one round.

For the poison needle trap, the mechanics description includes the only element that will trigger the trap: "nsuccessfully attempting to pick the lock triggers the trap." Presumably, this would include attempting to "pick" it with the wrong key, in as much as that is considered a lock picking attempt.

*******

This makes sense also. There is no mystical detection of a tool in the lock; it's just that if you tamper with the drums in the wrong way, you get stabbed by the needle. How does the mechanical trap recognize you have the wrong key? Because you didn't turn the proper drums. If you successfully pick the lock, you did turn the proper drums.

Plus, the user of that chest needs to open the chest to get stuff. That person uses the key. No need to disarm the trap. The key just opens the chest. Picking the lock successfully mirrors using the right key. It unlocks the chest and does not trigger the trap.

I agree that the wording of this trap could be improved. Notably, the wording in the general description of the trap does not mirror that used in the description of the mechanics. This is where the confusion originates. But, once you disregard the first part as a mechanic but rather as general description, to follow the format of all other game elements in this edition, it seems to make perfect sense to me.

That said, we're nitpicking pretty solidly here :), because in the end the DM does pretty much what the darn hell he or she wants with that trap in his or her dungeon :)
 
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Imaculata

Explorer
This makes sense also. There is no mystical detection of a tool in the lock; it's just that if you tamper with the drums in the wrong way, you get stabbed by the needle. How does the mechanical trap recognize you have the wrong key? Because you didn't turn the proper drums. If you successfully pick the lock, you did turn the proper drums.
You don't need mystical detection to notice that the inserted key is not the correct one. With a lockpick you could easily hit drums that you're not supposed to hit, and will trigger the trap. I think that's the whole point of the trap; that it triggers if you insert anything but the correct key into the lock.
 

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