D&D 5E Toll the Chest

[Hriston]

This is just silly. The cleric suspects that the chest is a mimic, and takes an action to check. Of course they won't be surprised if it turns out their suspicions were correct!

Suspects, not knows! A threat has not been noticed. For all the cleric knows, it could be just an ordinary chest. Before the cleric has a chance to confirm their suspicion, combat begins. Therefore, the cleric is surprised at the start of combat. The cleric thought they had time to cast their spell, but they did not.

 

[James Gasik]

So...how does one avoid being surprised by a Mimic? If you can't tell what it is, and even being suspicious and testing it isn't sufficient, does the creature always have surprise?

You would think that would be reflected in it's stat block.

 

[Crimson Longinus]

Suspects, not knows! A threat has not been noticed. For all the cleric knows, it could be just an ordinary chest. Before the cleric has a chance to confirm their suspicion, combat begins. Therefore, the cleric is surprised at the start of combat. The cleric thought they had time to cast their spell, but they did not.

Run it how you want, but that doesn't make any sense at all. A person will not be surprised by the their suspicion turning out to be correct.

If a player says that their character intently watches the red door in case the orcs will barge in, and then the orcs barge in via the red door, the character won't be surprised by that!

 

[cbwjm]

At the point where the party is suspicious of the chest being a mimic to the point they're trying to cast toll the dead, I'd say that no one in the party is surprised since they are all on guard in case it is a mimic.

 

[TaranTheWanderer]

If one were going to have a mimic make a check, I wouldn’t use stealth. It sounds more like performance or deception to try to pretend to be something you’re not. But since the mimic has an ability that makes them indistinguishable from a normal object, I would rule they automatically succeed.

If the players come back in the room, I might allow a perception check to see that the chest isn’t in the same spot if the mimic happened to have moved while they weren’t in the room. The only thing that nets the players, though, is that something moved the chest

 

[Hriston]

It doesn't matter if the cleric knows or not, the cleric was suspicious of it and was aware that it could be a danger. There's no way for that chest to get surprise on the cleric while the cleric is suspicious and testing it like that.

Everything could be a danger. Adventurers are suspicious of everything, and yet the game has rules for surprise.

This is a False Equivalence. Seeing a chest and being explicitly suspicious of it isn't the same as being unaware that something is around the corner. Even if being alert, something sneaking up on you can surprise you. The two situations are not the same.

To me, it's exactly the same. How does this approach not devolve into players constantly declaring they're suspicious that every inanimate object might be a mimic and that every corner might have a hidden creature lurking around it to avoid being surprised when they happen to be correct?

 

[Maxperson]

Everything could be a danger. Adventurers are suspicious of everything, and yet the game has rules for surprise.

You are required to be completely unaware of the enemy for surprise to happen by RAW. They have noticed the chest so surprise isn't possible if they are suspicious, whereas the group has not noticed the stealth Mind Flayer around the corner.

To me, it's exactly the same. How does this approach not devolve into players constantly declaring they're suspicious that every inanimate object might be a mimic and that every corner might have a hidden creature lurking around it to avoid being surprised when they happen to be correct?

Two interconnected reasons prevent it from devolving into that. The first reason is that you very rarely use mimics. The second reason is that because you very rarely use mimics, they will waste a ton of time poking at normal crap and become bored with it very quickly.

I think the only reason the OP happened is that treasure chests are virtually never just left alone in the middle of a non-descript room. That encounter was just asking for PC/player suspicion.

 

[Hriston]

Of course general awareness that any object might be a mimic doesn't make you immune to surprise (even from mimics!). But taking unusual precautions against a specific object being a mimic shows that the character must be aware of the threat posed by that object.

What threat? For all the cleric knows, it's just a normal chest that poses no threat whatsoever. No actual threat has been detected. It's just speculation.

The rules are written that way so that a character who notices one or more (but not all) of the members of an attacking force still gets their action on the first round of combat. They noticed (some of) the threat and so they can act against the threat they noticed, even if they didn't see all the sources of that threat.

In my opinion, however, there is no reason to extend that rule to mean that characters who are wrong about the source of a threat are immune to surprise from completely separate threats.

For example, I wouldn't extend the rule to mean that guards escorting a hostile prisoner are immune to surprise from an outside threat that they failed to perceive. Similarly, the PCs can not render themselves immune to surprise by capturing a monster and making it go first down the hallway, even though they are immune to surprise from the threat posed by that monster.

Presumably, the threat represented by a prisoner or captured monster has been neutralized by the fact of its imprisonment, so these examples are kind of ridiculous.

 

[Crimson Longinus]

What threat? For all the cleric knows, it's just a normal chest that poses no threat whatsoever. No actual threat has been detected. It's just speculation.

Speculation that is correct! The threat is as good as detected. It is absurd to claim that a monster that the characters can directly see, to which their attention is focused on, could surprise them. The only way a mimic could do that is that the characters believe it to be a harmless object, which they in this instance absolutely are not doing.

 

[Hriston]

So...how does one avoid being surprised by a Mimic?

Easy, your Perception beats its Stealth check.

If you can't tell what it is, and even being suspicious and testing it isn't sufficient, does the creature always have surprise?

No, see above.

You would think that would be reflected in it's stat block.

Skills Stealth +5