A troll that is just walking by is only likely to walk by, because that's all he is doing. To be likely to do anything, it has to be 67% or more likely to happen.
""Likely" means greater than 66 percent. "More likely than not" means greater than 50 percent. "About as likely as not" means 33 to 66 percent. "Unlikely" means less than 33 percent."
That's, like, the opposite of a natural language definition of any of those words or phrases. I mean, where'd you get that? Glosses of
likely range from
probable to
possible or
plausible. I think it's at least plausible for a troll to cause damage or danger, don't you?
The problem is that is wasn't a threat before combat, so if we follow your procedure and not the book, we end up with the party not noticing the threat until combat begins and being surprised, despite seeing the troll.
I laid out my procedure in some detail up-thread. This is not it.
The only way it works out for the party to not be surprised is if noticing the potential threat = notice threat.
However you want to think about it is fine with me. It doesn't change how I would run the troll scenario, but noticing something that appears for all purposes to be an ordinary chest wouldn't count just because any and every chest could possibly be a threat. That way leads to madness. Everything's a potential threat.
This is wrong. It only includes situations where combat is 67+% likely to happen. It has to include all potentiality, which your definition of threat fails to meet.
Okay, just thought I'd help you out, but I can see you're married to your bizarre definition of the word
likely. I couldn't care less, personally.
Which would end up being a rules failure if it wasn't for that "The DM decides" that covers the oddball situations.
Indeed, why have rules at all? Just tell the story you've already made up about the cleric who was on guard against the mimic.
Really? You failed to see the cleric cast Toll the Dead on the chest to see if it was a creature?
That's not "an action to try to use their senses or awareness of the environment to detect the presence of a creature." It's casting a spell that starts combat. Once the cleric's turn in combat comes up, they can cast the spell. Clearly, I was talking about an action that would have made the party
aware of the mimic
before combat started.
So I shouldn't have a dragon fly if the player of the fighter makes the build choice to not have any ranged weapons. And I shouldn't have a creature turn invisible if no player made the build choice to be able to see invisibility. Because doing so would be negating those build choices.
I disagree with that. Build choices are inherently flawed and fail to work in 100% of situations. Hitting a situation where the build choice isn't working is just normal game play. Negation would be if I set it up so that the build choice almost never worked. A creature has special abilities and those abilities don't negate any build choices. They are designed to make the creature more challenging.
Okay, but do you disagree with what I
actually said? The cleric likely has the highest Wisdom of the party. Maybe they're proficient in Perception. The player made those choices in part so the PC would be good at detecting when creatures are present. The phrase
While the mimic remains motionless leaves room for uncertainty as to whether the cleric can distinguish the mimic from an ordinary chest, so by deciding it's certain that it remains motionless and can't be distinguished, you're saying that choice doesn't matter in this one situation.
What's really happening is you are negating the mimic's CR and making the fight far easier than it should be. I would hope that you would lower the XP value of the mimic so as not to over reward the PCs for a fight that was far easier than it should have been.
Look at page 280 of the DMG. False Appearance has
no effect on the mimic's CR.
You're being unfair to both. Unfair to the mimic by removing a good chunk of it's challenge rating, and unfair to the players by removing the cleric's agency and surprising him despite the impossibility of surprise in that situation.
Both of these claims are false. I've already shown how the mimic's CR is unaffected by it having False Appearance, so no part of its CR could be removed by calling for an ability check. Also, calling for a Stealth check respect's the cleric player's agency in giving their character a high Wisdom score. Furthermore, surprise is far from impossible in this scenario because no one in the party, not even the cleric, has actually spotted the mimic for what it is.
Still is still. Still doesn't make noise. You're conflating a creature like a human, who is not naturally still with a creature like a mimic that has evolved to be still in order to survive. The mimic doesn't need to roll stealth to be still and therefore be silent.
Please quote me the lore that says the mimic is perfectly silent and still because it's certainly not in its stat-block.
All chests are potential threats to someone who doesn't have information about it yet.
Right. This is what you're trying to sneak in with your "potential threat" houserule. It's complete rubbish. Everything's a potential threat. Therefore, no one is ever surprised. The rules care about actual threats.
This is objectively false. The cleric in fact did notice the mimic. He just doesn't know that it's a mimic. If your PC suddenly appeared here on earth and saw an airplane high in the sky, he might think it's some sort of bird or dragon. Does he notice an airplane? 100%. Does he know it is an airplane? Not even a little.
It doesn't matter if the cleric knows it's a mimic. What matters is if they're aware of the actual threat in the room 15 feet away from them. As was described in the OP, the cleric lacked that particular bit of knowledge and was testing a mere hunch to see if it was indeed correct.