“The room appears to be empty” when it actually is.
“You see nothing of note”
“Empty”?
What are the mimics disguised as? Floorboards? Lint?
There was a necromancer tower in an early issue of Dungeon magazine. It had a stairwell with broken stairs and debris. A mimic had replaced one of the broken stairs. The only possible clue is the fact that there’s more rubble than there are missing stairs.
I had a DM make the entire house a mimic once. We spent like 6 turns of combat fighting a rug before we realized that was just the tongue.
Hit the uvula!
Relevant scene: Monster House, 2006
“Empty” is pretty contextual.
If you’re playing D&D 5e, no perception check, no matter how high, will let you notice an object is actually a mimic.
False Appearance (Object Form Only). While the mimic remains motionless, it is indistinguishable from an ordinary object.
What about the kind of evidence that leaves marks on the floor around where the mimic has been moving? Seems to me that’s fair game
Still, as a DM, it’s far too tempting to give a little bit of this away and join in on the hijinks.
Me: You find yourselves in a hidden library. On one shelf you see a series of tomes named “How Not to be Seen”, volumes I-XX.
Newbie Fighter: Oh sweet, those look handy.
Seasoned Rogue: Aw fuck. NOBODY TOUCH NOTHIN’!
Ten minutes later:

Lesson one: not standing up.
Well, is there some true sight or something that let’s you see a mimic?
Cool. Mimics breathe. Roll perception to see if you spot the motion of the mimic breathing.
“Motionless”
“Indistinguishable”
I’ll let you dive into that mystery on your own time.
while the mimic remain motionless
…Sorry, you’re acting smug, but I’m not sure what you’re even trying to say. Did you not read my comment? Mimics breathe. Breathing causes motion. Ergo, they aren’t motionless. If you can spot the motion, you can distinguish them from a regular item. If not, you can’t.
Breathing doesn’t guarantee that you can see something lol. Show me a breathing insect with its “chest” moving up and down. If you account for evolution then mimics who could best hide their breathing are also absolutely something that would happen. Plenty of mammals can hold their breath underwater a crazy amount of time. A mimic that could also position and shape its body would have no trouble hiding its breathing.
They’re motionless and indistinguishable and you’re just going to have to deal with that.
Bonus: the way to find them out would be to see if a character notices them looking out of place. Maybe it’s a contested stealth vs incestigation/perception role, or maybe the description of the room even has clues. There are absolutely other ways to “safely” discover them aside from breathing.
Of course it doesn’t guarantee it. That’s why you roll dice.
Does evolution apply to aberations? And would evolution not grant the same benefit to every living being as well? Not to mention, co-evolution would lead to better mimic detection, surely.
I don’t see why I have to deal with your fiction over mine.
My dude, I take your point, but you’re writing in properties for the mimic that aren’t in the rules, based on your real world perception of how things work. That isn’t applicable to the game mechanics. If you really have to have something to wrap your head around to explain the mimic both breathing and being imperceptible while impersonating an object, then model mimic breathing as some form of motionless skin breathing. Just realise that when you go digging for another reason to say why you can see it happening, its your model that is wrong, not the rules.
…you’re writing in properties for the mimic that aren’t in the rules…
The rules don’t say goblins breathe, either. If you can’t extrapolate that living creatures breathe, you’re not doing a good job.
…to explain the mimic both breathing and being imperceptible
I’m quite clearly doing the opposite, though. As does the lore attached to it, which clearly says “a mimic in its altered form is nearly unrecognizable”. Nearly unrecognizable means it is recognizable.
…some form of motionless skin breathing.
Okay, now you’re the one writing in properties that aren’t in the rules. Especially since its skin can be just wood.
…its your model that is wrong, not the rules.
No, neither are wrong. You just misunderstood the rules. And my model. The rules say they are indistinguishable when motionless. I say they aren’t motionless. No contradiction.
Couldn’t the mimics just hold their breath for a long time? I also see no problem with them having a physiology so different that their body literally doesn’t move when they breathe, but I don’t play D&D, so maybe I’m missing something with that.
In Dark Souls, mimics breathe slowly. Like, 17 seconds per breath. It’s tough to spot, but you can spot it if you’re cautious. Since it’s proven to catch people off guard, but CAN be spotted, I figure, why not use what works?
Yea and the pile of bones and gore next to the chest is purely coincidental
This is why I ask players what they want to do before calling for rolls after describing an area.
Once checks are called, all decided actions are locked in, then I narrate how the scene plays out based on the rolls. If a perception check is needed for traps, they have already confirmed what they are currently doing and can’t meta game around the consequences of it from having rolled low beforehand.
If their actions are to search for traps, then they do so, but if they roll low, they are still considered to be actively searching and thus, I will narrate that they triggered the trap while searching due to the low rolls. This also has the bonus of letting people with good intelligence but low wisdom substitute Investigation in the place of Perception.
If it’s in battle, perception is rolled for traps when stepping into the square of a trap. If passed, you spot it and are assumed to be actively avoiding triggering it (cause remember a square is a 5×5 foot area, not simply a single tile or something); if you failed, then well sucks to suck.
This way, players can’t mind trap themselves into doing nothing because they are constantly paranoid about their low rolls.
I like how pathfinder 2 has the concept of secret roles baked into the rules.
I have my players character sheets open at all times and roll for them when they search a room.
Keeps everyone in their toes and eliminates meta gaming
GURPS has an official GM Control Sheet for you to fill out with your PCs base stats and things like Perception. This supports their recommendation in the rule books to secretly roll any check where the PC wouldn’t really know if they failed. It’s fantastic.
Considering that was probably penned in the late 1980’s, why isn’t that standard kit for every other system?
Because in my experience meta gaming like that is not an issue at 90% of all tables. And at the other 10% it’s just that one guy that causes an issue about trying to meta game their character out of consequences.
RPG Rules are not laws, so they are not written for the lowest common denominator, but for a group of well meaning, socially functioning, above room temperature IQ human persons with a base level of trust.
Not every table preference has to be mentioned in the rules to be legitimate. At my table, there are no secret rolls or checks that a PC makes without a reasonably clear concept of what the consequences of success and failure are. So a list of default stats that your GM can check would be a waste of time and book keeping. If your GM likes to use mystical rolls with undefined consequences and the percussion of hidden dice to increase tension, more power to them. But to me that seems a waste of everybodies time.
I don’t know much about anything before 4e, which is my reference here. But yeah, it really should be. I jumped ship on D&D because they were just getting so lazy on mechanic content.
I think it might be more widespread than WotC, but my only experience is a distant smattering of PF2, D&D 5e, and GURPS 4e ever since. But I wouldn’t be surprised if the lack of attention to detail for actually running the game is a broad problem.
We can’t really put all the blame on the devs though, I think GMs who forget that it’s their table, and some rulebook isn’t the boss of them, make devs feel pressured to not “impose” rules and features in their sourcebooks.
Like homie, give me tools. You’re not holding a knife to my throat, I can chill on the nitty gritty if I want to. But give me the nitty gritty so I can decide for myself.
I dunno, I made my choice, I think it’s the best possible choice for my play philosophy. I think if more people considered my play philosophy, it would be the best possible choice for a lot of people.
Exactly. Pragmatism wins the day. Or at least it does at my table.
I’ll have to shop around for more and better tools. Thanks for reminding me that there’s a wider world out there.
But give me the nitty gritty so I can decide for myself.
This resonates with me. But I also have to give an obligatory nod to Palladium Games where the nit and grit is the entire point. If you’ve never had the pleasure, the RIFTS character sheet makes (American) taxes look easy to file by comparison. You practically need a session zero and a session zero-zero to get started.
You really should dive into GURPS. Chris Normand has a good YouTube series in the basics, but the gist is that it’s both the simplest and most intricate system out there. Basically everything is a 3d6 skill check, but there are thousands of pages dedicated to figuring out exactly what modifiers apply. The modularity is delightful, basically every rule is entirely and explicitly optional
Ugh, I remember years ago my players threw an absolute fit when I tried rolling behind the screen for their checks without telling them. I appreciate that it’s actually baked into the rules in PF2e
While I like my system, there are situations where I would really like to have rolled behind the screen because the thing they rolled for is a secret door or something and now they are asking questions why I called for a roll but nothing special happened in my narrative pertaining to it.
I’m not a DM, but I think the common advice is “randomly roll dice for no reason occasionally so the players can’t rely on dice rolls being significant.”
Unfortunately, if a trap goes off or they do spot one, players will tend to question why they didn’t get to roll anything and you have to explain that you were rolling for them behind the screen. Less the fact I’m rolling and more that they didn’t get to roll at all.
My players took great offense to that when it happened, unfortunately, as the rules at the time didn’t really support the DM having that authority.
So, I’m happy PF2e now has it baked in so that DMs are officially able to utilize that method of secret rolls.
Traps are puzzles. Even if they didn’t roll high enough, you should still describe enough about their environment that they could reasonably deduce that a trap was there.
https://theangrygm.com/traps-suck/
(I don’t always agree with everything this guy says - especially when he strays away from the topic of games - but he’s absolutely right about traps.)
Disagree. that just erases the point of using dice and having consequences for missing the checks.
I’ll continue to use my system as described above for traps.
Who advocated for removing dice rolls? There’s still plenty of room for dice rolls here, but it makes traps more interesting and engaging instead of a boring save-or-suck you blindside players with.
I’m every part of that meme and I like it! 😁










