How to roll perception checks for characters who aren't actively looking without arousing suspicion?

This applies to all d20 systems, but with an example from the from the Pathfinder PRD (emphasis mine):

Stonecunning: Dwarves receive a +2 bonus on Perception checks to potentially notice unusual stonework, such as traps and hidden doors located in stone walls or floors. They receive a check to notice such features whenever they pass within 10 feet of them, whether or not they are actively looking.

In this case, does the GM roll the check in secret or ask the player roll the check?
If the GM asks the player to roll for the check, what stops situations like:

GM: (interrupting) "Gimli, Roll a perception check."
Dwarf player: "Oh, it's a natural one, I guess I don't see anything."
Human player: "Okay, I'll roll a perception check for anything unusual in this room. Nice! 19. How about 19, does 19 work for you?"
GM: "Gimli, everything looks kosher to you. Aragon, you notice a rock coloured tarp on the ground here, covering what looks like a pit trap."

In this case, by telling the dwarf to roll his "free" perception check, he's telegraphed to the players that there is something to notice.

How can this be fixed, without bluffing checks for nothing in particular to throw off the signal to noise ratio of similar checks?

• I am confused by "They receive a check to notice such features whenever they pass within 10 feet of them, whether or not they are actively looking.", because I have always believed that everyone gets automatic checks for something that might catch their eye, and moreover that this is the difference between spot and search. – Random832 Aug 31 '12 at 14:29
• @Random832 so each time a party enters a room, you'd give them automatic checks for everything in that room? So, for you, a party of 4 entering a room with 3 traps would result in 12 perception checks? – StuperUser Aug 31 '12 at 14:32
• @Random832 Or do you mean like this? rpg.stackexchange.com/a/8342/3819 – StuperUser Aug 31 '12 at 15:27
• Possible duplicate of: rpg.stackexchange.com/questions/4155/… – RMorrisey Sep 1 '12 at 16:54
• Note, and this is very important: Natural-1s are not automatic failures on skill checks. The game behaves very poorly to treating them as such. Granted, a 1 indicates a poor roll, and a player with a mediocre bonus might intuit that 1 + that bonus isn’t likely to work, but there’s still a big difference there. – KRyan Mar 16 '15 at 19:54

Easiest way is to note the players perception skill (and other useful info) on a stat reference block and make the roll yourself.

This means you're making a roll for some reason however, which may get the players meta hackles twitching.

An option to avoid this that doesn't even involve rolling a dice (if you don't even want that to be seen) is pre-roll a load of d20's on a scrap of paper; cross each one off as you use it in turn for these "secret rolls".

Or you roll extra d20 random rolls all the time, for no reason at all. This has the added advantage of making the players more paranoid ;) (this is rather than the players making extra pointless rolls) you can speed up this with coloured dice with one colour per player and roll a bunch of them.

Hopefully however players can simply ignore these perception checks without the meta. Related: ( How do I use Passive Perception to have some characters notice parts of the environment? ) Never forget "Never ask your players for a skill roll you don't want them to fail."

• Nice. Lots of good approaches. I play a lot of poker, so should have high enough DEX and CHA to be able to roll without raising suspicion :) That's a good related question too, hopefully mine isn't a duplicate? – StuperUser Aug 31 '12 at 10:13
• Bonus points for smiling and then "trying to hide the smile" after making a fake roll. Or asking for a random bit of information from a particular character sheet and then making a note and looking concerned. Do this enough and when you roll an actual perception check for them and they flub it they'll have no clue. – aslum Aug 31 '12 at 14:57
• @aslum "If you have the Deceitful feat, you get a bonus on Bluff checks." – StuperUser Aug 31 '12 at 15:12
• I used to have players roll passive perception each time they entered a new "area", and use that for all objects in that area. Players would remain oblivious as to if the roll was even used. Then nothing is given away. – Mooing Duck Nov 5 '14 at 17:35
• Another +1 for player paranoia :) random rolling is my favourite trick! – Commander Coriander Salamander May 6 '15 at 3:48

Since you didn't specify an edition I'll chime in with how 4e does it which is assigning a passive perception which is perception skill +10. Obviously in this situation the dwarf would also get his +2 bonus. This would let you avoid the meta awareness/stop the game itself from inhibiting the story.

• So, passive perception is, essentially, state of constantly having rolled a particular perception. E.g. A dwarf has a passive perception for traps like this of 12. When passing within 10 foot of a trap with a perception DC10, he would automatically notice it (since 12 > 10), but for a similar trap with DC15 he wouldn't (since 12 < 15)? – StuperUser Aug 31 '12 at 13:46
• @StuperUser You didn't specify a version of D&D in your tags, hence the relevance of passive perception. I know for a fact its not in 3.5 or pathfinder, but was suggesting it as a fix that you could work into your game/DM style to avoid the issues you have with the system as is. And yes its like a perma roll perception check that is on except when you are actively searching for something, and thus rolling a perception check. – Joshua Aslan Smith Aug 31 '12 at 15:29
• Nice, I like this one, saves rolling. – Rob Aug 31 '12 at 16:38
• @StuperUser - Passive perception may have only been introduced in fourth edition, but it is only really the same as taking 10 in third edition, which is how many GM's already handled this situaton. – Mark Booth Aug 31 '12 at 23:39
• @Rob: We house-ruled the two passives into our Pathfinder game for that very reason. – Scott Pack Sep 1 '12 at 1:19

First, you need to have players roll BS checks from time to time. Don't do it for every single room, that's tedious. Just now and then. This is part of the story telling aspect of Role Playing Games, everything should not always be as it seems. You are not the players' friend, you're the enemy, they're playing "against" the NPCs through the DM/GM/CK.

When you come across something where Gimli gets that check, have all players roll. But only the players who specifically get that check count. So Aragon rolls, but it doesn't matter if he rolls a 20, he doesn't have the ability and his roll never meant anything to begin with.

Let's summarize several techniques others have mentioned, plus one of my own.

1. Avoid secret rolls entirely. There's something to be said for asking a player "Do you reckon Gimli would notice the pit trap in this room, or walk right into it?" It makes the players more involved in creating the story, but does require them to make a lot of decisions, and be willing to get their characters into trouble at least some of the time. They can still choose to roll and see what happens.

2. Trust the players not to meta-game. "Try to proceed as if the dice aren't there - don't say 'Uh-oh, I think I just failed a Spot check.'" In this case it doesn't matter who makes the roll, so it might as well be the player since many like having their destiny in their own hands, so to speak.

3. Let them meta-game. An occasional "I've got a bad feeling about this [roll I just failed]" can be funny and not too disruptive. Though if you're considering choosing this intentionally, you might want to take a look at #1.

4. Roll in secret, but throw in red herrings. I've been known to roll for the number of patrons in a bar, the weather, or just for the sound of it, and PC's stop reading too much into it. But OP's looking to avoid having to do that, so let's look at more mechanical solutions.

5. Use passive checks, as in 4e and 5e. Essentially, you assume that someone not specifically searching will get an average result (10+mods). Doesn't make a sound as long as your GM notes are in order. A bit predictable, and folk with lower skill will never spot something the best PC doesn't, which may or may not bother you.

6. Roll up a bunch of checks in advance for each session. More work than passive checks, but more variety. Players can still roll their own if they want, they just won't know when they come up.

7. Use graduated rolls. Walk into an interesting new area, roll Perception. Low rolls get the basic room description. Maybe DC 10 will see something mildly interesting. DC 15 or 20 may see something well hidden or whose significance isn't immediately obvious. Players do have an idea if they did well or tanked, but otherwise don't really know if they succeed or fail because you're describing something to them regardless. This one's my favorite, along with a bit of 2, 3, and 4 in moderation.

Separate from all of these, but important when you're thinking about these issues: make sure you had a good reason for rolling in the first place. As the Angry DM would say, only roll if there's a chance of success, a chance of failure, and a consequence for failure. If you think Gimli would definitely see that poorly concealed pit, just tell the player it's there. If the PC's say they're searching the treasure room and there's no particular time pressure, just let them find everything there is to be found by searching.

• Passive checks are in 3e/3.5e too, called "taking 10." – mxyzplk - SE stop being evil Sep 16 '16 at 21:22
• @mxyzplk That's not reeeeally the same thing, though, is it? Like, mathematically, yes, it's 10+ bonuses, but as a game mechanic I remember it being described as intentionally taking your time to guarantee an average result. Someone looking in those rules for a solution to this problem might not see the relevance, though I hear it was adapted to this purpose as a fairly common homebrew. – SirTechSpec Sep 17 '16 at 1:13
• Which is why I mention it. – mxyzplk - SE stop being evil Sep 17 '16 at 3:00