Assume you are playing a game where there is some mechanic (skill, thief ability, etc) for detecting traps. What do you think actually constitutes a trap? How far does that mechanical ability stretch.

For an example: There is a bell hung on the inside of the lid of a treasure chest. Opening the chest will cause the bell to ring, which will cause a monster (who has been trained to come when it hears the bell) to come and attack whoever is opening the chest.

Is the bell a trap for the purpose of detecting traps?  Would your players be pissed if they used their thief skill to examine the chest for traps, you told them they found nothing, and they then opened the chest and got attacked by the monster?

Yes. That is very much a trap of the alarm sort.

Similar to some remote traps. You trip it and elsewhere something is happening.

The main thing with detecting traps is detecting the trigger or delivery system. The pressure place, the needle in the lock, the bell attached to the chest, the snakes in the chest, the tripwire across the hall. The explosive runes on the floor. and so on...

Yes, an alarm bell triggered by opening a chest with the bell inside would count as a trap in my book.

I don't know. If there was no trigger (such as if the bell is attached under the lid without a string, latch or mechanism) I wouldn't let them detect it unless they have some magical ability. I would rule that a regular thieves ability (such as that in D&D) wouldn't be enough.

Quote from: Technomancer;953639Is the bell a trap for the purpose of detecting traps?  Would your players be pissed if they used their thief skill to examine the chest for traps, you told them they found nothing, and they then opened the chest and got attacked by the monster?

Yes and yes, particularly if their method of examination would give them a reasonable chance to notice it.

Quote from: CanBeOnlyOne;953647I don't know. If there was no trigger (such as if the bell is attached under the lid without a string, latch or mechanism) I wouldn't let them detect it unless they have some magical ability. I would rule that a regular thieves ability (such as that in D&D) wouldn't be enough.

Actually Id assume this is covered by thief abilities. Checking as they go for telltale signs. Pressure plates in front of or under, things concealed in the chest as open, etc.

Yep, that's a trap a thief could detect. Presumably, a thief would open a chest lid slowly, very slowly. Depending on his skill, he'd open the lid slowly enough so as not t set off the trap...once the lid is opened enough, he'd see the bell and go "hey guys, this chest has a bell alarm trap, prolly shouldn't ring it." Not all traps are of the "detect is one thing, disarming it is another" variety. Some traps (eg, the ol' 10' pit) are in some sense disarmed simply via detection.

Yes, Techno, this is an awesome trap.

If you're the GM, you must be congratulated for this trap.

If you're the players, you should be pissed--and pleased. A game isn't a game if it doesn't result in some unexpected surprises.

What, for that matter, counts as a trap for purposes of disarming?

If you have a rope bridge lined with bells and chimes (so that walking across it alerts the guards) should you be able to disarm it?

Quote from: Doom;953654Yep, that's a trap a thief could detect. Presumably, a thief would open a chest lid slowly, very slowly. Depending on his skill, he'd open the lid slowly enough so as not t set off the trap...once the lid is opened enough, he'd see the bell and go "hey guys, this chest has a bell alarm trap, prolly shouldn't ring it." Not all traps are of the "detect is one thing, disarming it is another" variety. Some traps (eg, the ol' 10' pit) are in some sense disarmed simply via detection.

What causes me to wonder is, unlike with most other traps, the cause isn't connected (physically or intuitively) to the effect; no wires, switches, gears, etc.  The thief may find the bell, but there is no obvious indication it has anything to do with the monster, especially if it is made to look like something ornamental.  Thief wouldn't automatically know it was an alarm.

So it's something I wouldn't begrudge them finding, but I don't think they should automatically know it is a trap.

I'd run it like this (assuming successful check):

"You slowly crack the lid of the chest and peek in. You notice a bell hanging from the lid of the chest that would have rung had you opened the lid quickly."

Most players will figure out that's an alarm, but I wouldn't tell them that.

Quote from: fearsomepirate;953693I'd run it like this (assuming successful check):

"You slowly crack the lid of the chest and peek in. You notice a bell hanging from the lid of the chest that would have rung had you opened the lid quickly."

Most players will figure out that's an alarm, but I wouldn't tell them that.

That's what I'd say. Except I'd make the character describe what he is doing.

I still follow the thinking of In The Labyrinth on trap detection. No trap is impossible to detect, but it may be very very difficult / unikely to detect.

But the fact something is thought of as a trap is different from the actual thing.
Also, the fact someone is thinking of searching for a trap is different from what they actually perceive.

So when someone says they are searching for a trap, they are searching for signs of a trap, and they get told what they see, which may or may not be something that is a trap.

Someone with a skill that gives an extra ability to detect traps will have a broader mindset of what to look for, and will get their perceptions described differently.

So I think about the actual situation in deciding how to set the chances of detection, and how to describe what the PC notices. Thinking of the bell trap, someone could maybe discover it either by looking from below through the crack with enough light while slowly opening the lid, or by maybe hearing or feeling an extremely faint sound or vibration of the bell moving before it rang, if it's very quiet and they can concentrate and aren't wearing gloves or a helmet or whatever. It also might be a very appropriate time to ask exactly what the PC does and give them a hard chance if they're peeking the right way, and a nearly-impossible chance of the other way unless they're extremely sensitive and the conditions are right. But even if they do detect it, what they detect is just a sense of something else moving or making sound other than the lid, unless they're actually seeing the bell (but they might only see part of the bell first if they're being careful, and not able to see what it is without opening it more.

Usually with traps, people are going to see something of the mechanism, something that could be or seems like a mechanism, and not "oh you can tell it's a trap that will do X if you do Y". And they may also get a lot of false positives, but people with trap detection skills may also be skilled at testing them more safely, though all of that will tend to take some time, too.

It is a trap if the referee decides it is a trap.

Quote from: Gronan of Simmerya;953764It is a trap if the referee decides it is a trap.

GM" Gronan... Your answer is a trap..."