D&D 5E Crawford on Stealth

[Caliban]

[MENTION=284]Caliban[/MENTION]: Another thing is that for all the concern over the risk of being surprised, in my experience, it doesn't happen very often. Only in particular circumstances does it seem to come up and I doubt even half of the combats I ever run or have played in have involved one side trying to get surprise on the other. Or maybe even way less than half. Others' experience my vary, of course.

I'm heavily influenced by my player experiences in the RPGA, Pathfinder Society, and Adventure League - i.e. it's very difficult (and often impossible) for PC's to achieve surprise unless it's specifically written into the module to allow it (a rare occurrence), but unless you have a high perception person in the group, the monsters will surprise you frequently.

Granted, it's usually because the PC's are being proactive and invading the bad guy's territory, so the odds are stacked in their favor as far as ambushes go, but still.

It basically comes down to: High Perception PC? Very few surprises (some are written into the mod so as to be unavoidable). All PC's have low perception? Frequently surprised. Hope you built them tough.

 

[Arial Black]

Again, the issue is the absolute perfection of passive scores. Let me show you. Let's instead of using one example, use 1 million of them. The guy with +10 will spot those DC 20 hiders 1 million times out of 1 million. The guy with +2 will fail 850,000 times. Now let's raise the guy from +2 to +10 and no passive perception. He still fails 450,000 times out of 1 million.

No. Our hero will not detect those hiders 1 million times out of 1 million.

Those hiders (lets give them Stealth +4, representing Dex 14 and proficiency, which I think is fair enough for a set of bandits). It's not 1 million out of 1 million; it's not even 20 out of 20.

Even if the DM rolls a single Stealth check for the group, then 17/20 they will be spotted by our hero (he is at +10 after all!), but 3/20 our 'absolute perfection' of passive Perception has our hero fail to spot them.

Not so 'absolute perfection' after all.

Your idea that a flat score means that there are no variables is belied by the game system which has the bandits rolling Stealth checks. I don't know what game you're playing, but 5E has no problem here.

 

[Arial Black]

By the rules it IS used to detect 'all the things ever!'. Your passive perception is always on and spots all secret passages, hidden items, traps, and hidden creatures within your line of sight all of the time as long as your passive perception is equal to or higher than the DC to spot something.

On a side note, it is interesting that JC decided to spell this out. I've been wondering how they actually felt about PP since I first read the book. It said PP existed and if it exists then it really should be the "floor" of your perception. But allowing it to be the "floor" means that a large number of traps become completely useless. It really changes the feeling of the game when in one game you say "I walk forward" and the DM says "You fall into a pit and take 10 damage" and you say "I climb out and keep walking down the corridor" and the DM says "You fall into another pit and take 10 damage" VS a game where the DM says "Your passive perception of 15 lets you see 5 pit traps within sight, each one is 5 feet by 5 feet. You can see where the edges of the pits are so you can just step around them."

I'm honestly not sure which type of game I like better, but the different rules create very different games.

Listening to JC's podcast and reading his 5E rules, that's not how 'always on' works.

For example, lets say that you (as DM) have set up a room with a cupboard, a chest of drawers, and a hatch door under a carpet. You've put a clue in the chest of drawers, a fancy cloak worth 50gp in the cupboard, and a carpet over the hatch.

For the clue: it's hidden among some papers so you've set the DC at 20.

For the cupboard: spotting the cloak is automatic as soon as you open it, but it's DC 10 to recognise its worth.

For the trapdoor/hatch: automatically spotted if the carpet is taken away.

What happens when the PCs enter the room? One guy has a passive score of 20 so he spots everything just by entering the room? No, that's not how 5E works.

In 5E, you tell the DM what your PC is doing. If no-one moves the carpet, no-one spots the trapdoor. If the carpet is removed than everyone present can see the trapdoor automatically.

If the cupboard is not opened then no-one can see the cloak and its worth is not an issue. If someone opens the cupboard they spot the cloak, and a passive score of 10 or better means that it's obvious it's worth a lot. If the passive score is less than 10 then if the player asks questions about the cloak allow them to roll and if they get 10 or more they realise the cloak's value.

If no-one opens the drawers then the clue cannot be discovered, no matter what your 'always on' passive score may be. Once a PC opens the drawers and searches them, if they have a passive score of 20 or higher then they spot the clue. If their passive score is less than 20 then let them roll as they search the drawers. If they roll 20 or higher then they spot the clue.

This is how 5E works and is intended to work. DMs need not fear a PC with high passive scores who just turns up and magically knows everything, because that's not how the game works.

 

[Caliban]

What happens if the PC with the high Perception says "I search the room". Do you make them list exactly what locations and items they are searching, or assume they check all the reasonable spots?

 

[Arial Black]

What happens if the PC with the high Perception says "I search the room". Do you make them list exactly what locations and items they are searching, or assume they check all the reasonable spots?

You can reasonable have them do it either way.

If you ask them to tell you what they are doing (not unreasonable since "What are you doing" is the most common phrase out of a DM's mouth!) then run it as detailed above.

If the players can't be bothered(!) and just want to 'search the room' then if you say that they didn't bother checking the drawers then they'll reply that of course they did! They checked everything! So as DM you must assume that they check everything. This means that you determine how much time it takes to do that and then tell them that it took them three hours and then they'll say that they searched quicker than that. So you impose disadvantage on their checks and passive scores (they'll whine) and because they said they were searching 'everything' then they open every drawer, every door, set off every. Single. Trap ("Oh, no, we're too careful!") and have to make saving throws.

If you determine that it's an uninteresting room then narrate the boring bits as quickly as you want. If the room is intended to be interesting then the players should be expected to tell you in detail what they do. They wouldn't expect to have a fight by saying "We just kill everything. Tell us what loot we got. My passive attack roll is 15".

 

[schnee]

Well, walking into a forest with a passive Perception of, say, 12 would also spot 20 hidden people in six seconds (if their Stealth check results were 12 or less, which is an average for average people); are you saying that because the +2 Perception guy spots 20 hidden people in six seconds that he is also quasi godlike?

Wait...

How much cover does each hiding person have due to foliage? Partial? 3/4?
What is the light like? Dim?
What other weather conditions are there? Mist? Rain?

Here's how I read it right now.

Lightly obscured? Try that passive check again at -5 as per RAW - their skill check is now 7. They do an active search? Disadvantage. In this case, an average person missing a few untrained people trying to hide in this situation is sensible. That same person passing by 20 of them in a short period of time is bound to find a few of them - either they hid poorly, or someone got tired and shifted their weight a bit and made noise that gave them away, or sneezed, or whatever. Seems fine to me.

Heavily obscured? Blindness condition, so automatic fail for passive perception for sight. Depending on other things, like taking time to really dig in I might actually offer Advantage on the hiding check. Active search has the same deal, disadvantage. An average oblivious person still has a good chance to see one or two of them, despite their best efforts, due to there being 20 of them and not being trained.

Am I wrong? If so, how?

 

[Maxperson]

No. Our hero will not detect those hiders 1 million times out of 1 million.

Those hiders (lets give them Stealth +4, representing Dex 14 and proficiency, which I think is fair enough for a set of bandits). It's not 1 million out of 1 million; it's not even 20 out of 20.

Even if the DM rolls a single Stealth check for the group, then 17/20 they will be spotted by our hero (he is at +10 after all!), but 3/20 our 'absolute perfection' of passive Perception has our hero fail to spot them.

Not so 'absolute perfection' after all.

Your idea that a flat score means that there are no variables is belied by the game system which has the bandits rolling Stealth checks. I don't know what game you're playing, but 5E has no problem here.

You guys keep trying to change this into something that it isn't. I'm talking specifically about DCs of 20 or less. Once again, because you can't seem to get it, I'm not saying that there will never be a DC of 21+ or other penalties at times. I'm saying that a passive perception of 20 is perfect 1 million times out of 1 million at detecting a DC of 20 or less. That would be impossible for anything humanoid.

 

[dco]

Listening to JC's podcast and reading his 5E rules, that's not how 'always on' works.

For example, lets say that you (as DM) have set up a room with a cupboard, a chest of drawers, and a hatch door under a carpet. You've put a clue in the chest of drawers, a fancy cloak worth 50gp in the cupboard, and a carpet over the hatch.

For the clue: it's hidden among some papers so you've set the DC at 20.

For the cupboard: spotting the cloak is automatic as soon as you open it, but it's DC 10 to recognise its worth.

For the trapdoor/hatch: automatically spotted if the carpet is taken away.

What happens when the PCs enter the room? One guy has a passive score of 20 so he spots everything just by entering the room? No, that's not how 5E works.

In 5E, you tell the DM what your PC is doing. If no-one moves the carpet, no-one spots the trapdoor. If the carpet is removed than everyone present can see the trapdoor automatically.

If the cupboard is not opened then no-one can see the cloak and its worth is not an issue. If someone opens the cupboard they spot the cloak, and a passive score of 10 or better means that it's obvious it's worth a lot. If the passive score is less than 10 then if the player asks questions about the cloak allow them to roll and if they get 10 or more they realise the cloak's value.

If no-one opens the drawers then the clue cannot be discovered, no matter what your 'always on' passive score may be. Once a PC opens the drawers and searches them, if they have a passive score of 20 or higher then they spot the clue. If their passive score is less than 20 then let them roll as they search the drawers. If they roll 20 or higher then they spot the clue.

This is how 5E works and is intended to work. DMs need not fear a PC with high passive scores who just turns up and magically knows everything, because that's not how the game works.

He said line of sight, something behind a wall, carpet, in a cupboard, etc are not in the line of sight.
But the DM may require the player to pass sometime there to spot those things instead of doing it automatically at first sight.

 

[Rod Staffwand]

Passive perception is only 'always on' when it is referenced in the rules--generally when it acts as a DC for a stealth check.

Passive perception is specified as an option to detect traps (and I think secret doors) in the DMG as a substitute for the perception check. None of the sample traps listed there mention passive perception as part of their resolution. I'm unfamiliar with most of WotC's adventures so I don't know how most of their traps are written, but unless they specified they can be found with a passive perception of X+, I wouldn't allow it.

A DM can certainly choose to go with using passive perception in finding traps and secrets. Such a DM and group would likely be less interested in the trap-finding aspects of the game and prefer to spend less time and effort on it. This is certainly a valid play decision.

I certainly wouldn't allow both passive perception and an 'active' perception roll to be used with the same action or activity. Passive perception represents with active effort of being watchful, as does rolling your perception. Using both at the same time is akin to giving a character advantage on the roll with one d20 being replaced by a 10. That's completely unsupported by the rules and the resolution methods for every other aspect of the game and I see no reason to make a special case for perception.

Where the passive perception 'floor' comes in is with hidden opponents that you cannot spot with your passive perception. Say the group is attacked by an invisible stalker who rolls 18 for their stealth check after attacking. Your passive perception is 15, thus the invisible stalker becomes hidden to you. You lose track of it. On your turn you want to try and find it, so you use the search action and make a perception roll. If you beat the 18 you find it, otherwise you don't.

Technically, your passive perception of 15 is still in effect, but that doesn't matter. If you rolled a 16 you did better, but still not good enough to find the stalker. If you rolled 8, you could replace that with the 15 and it still doesn't matter. Both passive perception and active perception are fails. Even rolling a natural 1 doesn't mean you spot 'less' than your passive perception. You spot the exact same thing--which is not the invisible stalker you're looking for.

As for high passive perception PCs spotting all ambushes, this is entirely fine. Ambushes are generally about who is surprised during the first round of combat. High-PP characters are less surprised. The other PCs would be. In any case, a combat results, possibly with the baddies still in a favorable tactical position. Honestly, the stakes are not that high that the DM should be fretting over it. If you absolutely feel you must ambush the party, have the monsters attack from out of secret doors or materializing out of thin air (especially at high levels of play). Monsters appear and attack. Simple as that.

 

[Majoru Oakheart]

This is how 5E works and is intended to work. DMs need not fear a PC with high passive scores who just turns up and magically knows everything, because that's not how the game works.

I said everything "within line of sight". All the things you mention are not within line of sight since they are blocked by something. You are correct, if it is impossible to see something because it is under a carpet or in a desk or a cupboard, you can't see it with your PP.

But often, as people above have said, players will say "I search the room" and then you have to determine if that involves searching under the carpet or in the cupboard.

Here's the problem: Some of the written adventures have sentences like "The PCs can find a chest hidden under the bed with a DC 14 Wisdom (Perception) check". In this situation, the chest may or may not be seen because it is under the bed(but part of it could be slightly visible) but the adventure lets Perception represent "how well you search the room" in addition to what you can see. This creates a weird situation where you have to determine whether each Perception check listed in an adventure is one that requires them to search the room or one they spot immediately.

Another good example is one that says "PCs examining the mural can see the following details with a DC 15 Wisdom (Perception) check..." If the PC can see the mural from across the room, does that mean they automatically spot the details or does "examining" require you to be closer or take more time, even with a high PP?