Active Perception and Passive Perception

[Mengu]

Passive Perception: The excuse that the DM uses to tell you about stuff.

Aggressive Perception: The tool you use to find and shoot the hidden gnome.

 

[Nichwee]

If peeps really want to put the interest back into the idea I would make it that the Passive Perception is used by the DM to go "All those with PP of X or more make an active perception check" and then use those to determine who, if any, spotted something hidden.

Basically all those of PP high enough know something looks out of place but can't work out why, so they all nake an active check to see if any of them spot why they think it looks off, or if they just shrug it off and assume they are being paranoid.

This trick works best if you trust your players not to metagame the fact you just highlighted that an active perception is a good plan, or you do it sporadically when pointless to keep players guessing, or you just roll the needed checks for them so the players don't even know why those 3d20 just got rolled. And then announce, to any PC who spotted something, what they saw.


In our group we normally use the idea that the PP is just a lower limit to the check when we would/do make one anyway (such as 'on watch' or when we are searching a room slowly = PP for quick look around, roll for active look around, highest is our result). However we/DM will impose our own penalties due to RP such as "My character was doing XYZ so I don't get a check at all"/"My character was doing XYZ as well, any penalties?""Take a -5!".

 

[Kingreaper]

Hmmm, good points, Prism. I may have to rethink having encounters roll Stealth against passive perception, as that doesn't solve the "the ranger sees everything the rogue sees and more" problem.

A possible solution: Flip a coin, or roll a D6, or whatever, to decide if any given character was looking in the right direction.

Then, sometimes the Rogue spots something the ranger doesn't. Why? Well, the ranger, while very perceptive, also has a love for fine upholstery, and the curtains in the room were simply exquisite.


It ends up working similarly to why multiple PCs might have Heal trained. Sure, only one of them needs to use it, but that one's not always gonna be where it's needed.

 

[Colmarr]

If I was playing the rogue above I would want to thing that sometimes we would all spot something, often the ranger would see something I missed and occasionally I would see something the ranger missed. We are only +2 apart in skill level. How does that work with passive perception?

Two words: Active stealth.

Sometimes the ranger will passively spot a hiding enemy that the rogue doesn't and vice versa.

And again, this problem only arises if the DM sets their DCs with the PC's perception scores in mind. If you raise the default DC from 15 to 16 or 17 because you know the ranger has passive perception 17 and the rogue 15, then that's a failure of immersion by the DM.

If you raise the default DC to 16 or 17 because you know the Whitefang kobolds are masters of misdirection even by the standards of their scaly kin, then there's no problem at all.

But even putting that answer aside, if two characters are only 2 points apart in Perception bonus, then it's unreasonable of one or both of them to feel that they should be substantially better or different to each other. It's not a problem with passive perception - it's a problem with player expectations.

 

[Kingreaper]

Two words: Active stealth.

Sometimes the ranger will passively spot a hiding enemy that the rogue doesn't and vice versa.

Not with passive perception, unless you add some randomiser on the other side.

The one with the higher score will ALWAYS see what the one with the lower score sees, making the lower score irrelevant.

That's where keeping track of (and even just randomising) who actually has a CHANCE to see it becomes useful. Because sometimes the rogue and the ranger don't have the same field of view, and then the redundancy becomes useful.

 

[DracoSuave]

Not with passive perception, unless you add some randomiser on the other side.

Active Stealth. The above still stands.

The one with the higher score will ALWAYS see what the one with the lower score sees, making the lower score irrelevant.

Unless the stealth roll is between both, in which case, the stealthed character is hidden from the lower character, and not the higher character. This matters a great deal when 'combat advantage' tends to mean 'massive damage' with stealthy monsters.

That's where keeping track of (and even just randomising) who actually has a CHANCE to see it becomes useful. Because sometimes the rogue and the ranger don't have the same field of view, and then the redundancy becomes useful.

That is correct, for things that are above the Ranger's PP.

 

[DracoSuave]

Its not so much the problem with the actual DC but with the static nature of the passive check. Lets say as the DM you follow the guidelines to some degree and set the DC for spotting traps, secret doors and opponents to 19 for your 8th level party. The 14 WIS perception trained ranger will spot everything all the time with their +11 check. The 10 WIS perception trained rogue will also see everything. The untrained WIS 20 cleric also sees everything. The ranger doesn't feel special at all even though they are considered the party spotter.

So you decide to change the DC slightly to 20. Now the rogue and cleric see nothing and the ranger probably feels important again. The rogue wonders why he bothered training perception at all. The cleric still has other things going on with 18 WIS and probably isn't as bothered

So what do you do? You vary the DC? This is exactly the problem - you are choosing who gets to see each thing with no random element and no dice rolling. Surely that is fine sometimes but everytime? The players will possibly begin to feel out of control of the situation. The DM decides if the ambush should or should not be spotted.

The thing to understand here, is that this is the players' choice. They have decided they want someone who autodetects most things. And I'm cool with that, it speeds up play. But, I introduce higher levels of detail that are valuable to the party to -reward- this sort of character creation.

Your way:

Ranger has Passive Perception 24. So to make a roll for something, you need to exceed that.
Secret doors are DC 25. The characters roll off, and if any player finds it, the ranger does. The door gets opened after the warlock finally makes a difficult Thievery check to unlock it.

My way:

Ranger has Passive Perception 24. The door's DC is 20. The ranger automatically finds it, but does not automatically find a certain loose panel. The Thievery DC is difficult for the warlock, but the ranger's finding the loose panel allows for a bonus to the warlock's check, as that panel can be jimmied open and the inner workings used to circumvent the lock itself.

 

[Merlin the Tuna]

On the subject of auto-detection...

I don't actually have a PHB -- does 4E perception still use the 3.5E rule of characters taking -1 to Spot/Perception per 10 feet? If not, that seems like it would be a reasonable compromise for passive perception. So if the Rogue has a passive perception of 20 and the DC to find the hidden panel in the wall is 20, he'll find it automatically, but not until he's standing right next to it. If the DC is 19, he'll notice it as he walks by from a few feet away, and so on.

 

[Prism]

Yes you still apply a penalty for being a distance away but I think its 10 squares iirc.

This has been a useful thread for me. I have come to a few conclusions about what I will try over the next few weeks. I am going to use passive perception without raising the DC for many things - appraising the general details of a room, spotting clues I might give about a hidden trap, seeing a non hidden encounter type trap, noticing something important about an opponent or in a skill challenge.

However I'm also going to mix in some hidden stuff - stuff that will require a full 1 minute search for as per the PHB. Things like secret doors, hidden one off minion traps, extra treasure which has been stashed. If the players want to find a shortcut via a secret passage I want them to decide to search in the right place rather than just give them it without effort on that part. I want the players to feel they were sometimes lucky, or made a good call to search an area than give them everything on a platter. I like the idea that sometimes passive perception can give you a clue but an active is needed to make it easier. We enjoyed this aspect in previous editions and I don't want to remove it totally

This of course goes against the advice in the DMG to apply passive perception as soon as they have the chance of spotting a trap. However thats because 4e assumes traps are now in combat encounters and you don't want to trick your players. Secret doors seem to have all but disappeared and if they do exist it seems expected that the party finds them (whereas I aim for the opposite)

 

[KarinsDad]

The thing to understand here, is that this is the players' choice. They have decided they want someone who autodetects most things. And I'm cool with that, it speeds up play. But, I introduce higher levels of detail that are valuable to the party to -reward- this sort of character creation.

Your way:

Ranger has Passive Perception 24. So to make a roll for something, you need to exceed that.
Secret doors are DC 25. The characters roll off, and if any player finds it, the ranger does. The door gets opened after the warlock finally makes a difficult Thievery check to unlock it.

My way:

Ranger has Passive Perception 24. The door's DC is 20. The ranger automatically finds it, but does not automatically find a certain loose panel. The Thievery DC is difficult for the warlock, but the ranger's finding the loose panel allows for a bonus to the warlock's check, as that panel can be jimmied open and the inner workings used to circumvent the lock itself.

I think "your way" can be used in "his way".

There is nothing special about "your way" example except that you decided that you would throw in an extra panel that you didn't throw in for "his way". That same panel could exist in "his way".

The PC rolls DC 25 and finds the secret door. The PC rolls a different DC 28 and finds the secret panel.

And doing it "his way", the PC might find the loose panel without finding the secret door (he fails the first check, but makes the second). Then it becomes a bit of a mystery for the players to explore.

That option cannot happen in "your way" because your system (like Passive Perception in general) erroneousnessly assumes that if something is slightly easier to noticed, it will typically be noticed if the slightly more difficult to notice something is detected.

That's far from true. I can find the lost keys hidden under the chair and never notice the glasses sitting on the arm of the chair.


And your method ignores his point that the Ranger is +15 to the roll whereas the Rogue is +13 to the roll. The Rogue rarely feels special because the Ranger is just a hair better. But the Rogue also dedicated a lot of resources to Perception. Why exactly did the Rogue dedicate all of these resources, just to be equaled or outshined by the Ranger most of the time?

If a roll is made most of the time when it's something worthwhile, than the chances of the Rogue making it when the Ranger does not occurs more often than when some high percentage of the Perceptions are Passive Perceptions. The player's belief that the Rogue's Perception skill is valuable is increased.


There's nothing wrong with rolling the dice to get random results. It's really what makes the game interesting and unique. Blurting out a bunch of info because a player maxxed an ability? Not so interesting.