D&D 5E Rolling for Passive Perception

[Quickleaf]

I'm thinking of trying out something strange as a DM regarding Passive Perception.

As it is, I use Passive Perception in two ways:

1) When a character enters a setting, they perceived everything their Passive Perception would allow: hidden creatures, treasures, etc. Usually for secret doors and traps I give big clues and invite the character to look closer.

2) When a character rolls a Perception check, their Passive Perception is their floor- the lowest result they can get. If they roll below their Passive Perception, I just use their Passive Perception.

This does, however, make adventure design a little weird. In a way, I have to think of what a realistic DC would be for spotting something, but at the same time I just know flat out some of the characters are going to be able to beat it with their Passive Perceptions.

For example, in next week's adventure the characters are going to enter a dungeon room with a trap: a net will fall, and two flying swords will attack.

If I set the DC of spotting the net at, say, 14, I just know two characters will see the net. Why put a net there at all in that case? If I set it at 18 then no one will see it, but is that realistic? And why use Passive Perception at all if I'm just going to juice all the DCs?

So what I've decided to do is to roll during the session to set the Perception DC. Rather than preplanning a DC of 11 or 14 or 16, I'll write down +1 or +4 or +6. Then, when the characters enter the room, I'll roll for it and note the DC. Maybe I'll roll super low and everyone will see it. Maybe I'll roll super high and no one will. But either way it reduces my own meta-game thinking when planning the adventure.

Plus it's fun to roll dice, and I love random elements in adventure design.

So what do you think? Am I crazy? Do you do something similar, or is this just not a problem for you?

My thought process is... what's the point of rolling to perceive something? Why does that mechanic exist?

I think the answer is... as a form of threat detection and/or mitigation.

I DO NOT think the answer is... to have a mechanic that acts as a buffer between the player and the narrative.

In other words, players should not be chomping at the bit with "I want to make a Perception check." Because once you need to ask, things are already on the cusp of going pear-shaped. Because it's about threat.

So for my own house rules, I prefer to use Perception as a saving throw in response to an ambush happening or a trap being triggered. It's the "do I notice something at the last second to avoid being surprised by this?" That's the purpose of the mechanic.

This approach also involves less rolling (which is the point of Passive Perception), but it's a paradigm shift. For example, this means I can't settle for assigning DCs to detect traps and secret doors. Instead, I have to engage the fiction as a GM.

 

[Charlaquin]

I'm thinking of trying out something strange as a DM regarding Passive Perception.

As it is, I use Passive Perception in two ways:

1) When a character enters a setting, they perceived everything their Passive Perception would allow: hidden creatures, treasures, etc. Usually for secret doors and traps I give big clues and invite the character to look closer.

2) When a character rolls a Perception check, their Passive Perception is their floor- the lowest result they can get. If they roll below their Passive Perception, I just use their Passive Perception.

This does, however, make adventure design a little weird. In a way, I have to think of what a realistic DC would be for spotting something, but at the same time I just know flat out some of the characters are going to be able to beat it with their Passive Perceptions.

Yep, this is definitely a thing that can happen with passive perception, especially when you treat it as the floor for perception checks. Personally, I don't really have a problem with setting a DC knowing that a PC can't fail to meet it, but I can easily see why this might bother a DM. One of the advantages of using passive perception only as the PHB recommends: to represent the net result of an action performed repeatedly or continuously over a period of time. Basically, ignore the name "passive perception," and instead treat these as a special type of check used when a player declares an ongoing action.

For example, in next week's adventure the characters are going to enter a dungeon room with a trap: a net will fall, and two flying swords will attack.

If I set the DC of spotting the net at, say, 14, I just know two characters will see the net. Why put a net there at all in that case?

Well, I would argue that if the net isn't interesting if you know two characters will see it, then it isn't interesting at all. In which case, I would say it shouldn't be there at all. But there are other schools of thought with regards to traps and other hidden elements. For some DMs, "because it would make sense for a net to be there" is reason enough for it to be there, regardless of if its discovery or lack of discovery is interesting. But personally, my recommendation would be to change the way you think about these traps and hidden elements. The interesting part shouldn't be the question of whether or not the PCs find it, but what they will do about it when they do find it.

If I set it at 18 then no one will see it, but is that realistic? And why use Passive Perception at all if I'm just going to juice all the DCs?= the m

No point. If you're going to raise the DCs to account for the players' bonuses, it's just a treadmill, which I'm not a fan of. I'd definitely advocate for just following the "10 = easy, 15 = medium, 20 = hard" guideline and not taking the PCs' bonuses into consideration at all.

So what I've decided to do is to roll during the session to set the Perception DC. Rather than preplanning a DC of 11 or 14 or 16, I'll write down +1 or +4 or +6. Then, when the characters enter the room, I'll roll for it and note the DC. Maybe I'll roll super low and everyone will see it. Maybe I'll roll super high and no one will. But either way it reduces my own meta-game thinking when planning the adventure.

Plus it's fun to roll dice, and I love random elements in adventure design.

So what do you think? Am I crazy? Do you do something similar, or is this just not a problem for you?

I'm not sure I fully understand what you're describing here, but in principle, I feel like semi-randomized DCs is a perfectly reasonable concept. Maybe instead of the standard DC scale, easy is 1d6+7, medium is 1d6+12, and hard is 1d6+17, or something like that. I kinda like that, actually.

 

[Pedantic]

I'm not sure I fully understand what you're describing here, but in principle, I feel like semi-randomized DCs is a perfectly reasonable concept. Maybe instead of the standard DC scale, easy is 1d6+7, medium is 1d6+12, and hard is 1d6+17, or something like that. I kinda like that, actually.

The proposal is more a straight reversal of the rolling dynamic. The trap or hidden feature's DC is converted to a bonus that's rolled vs. the PC (really, you're just subtracting 10 from the DC and adding +1d20, and the PC is adding 10 to their modifier).

 

[Charlaquin]

The proposal is more a straight reversal of the rolling dynamic. The trap or hidden feature's DC is converted to a bonus that's rolled vs. the PC (really, you're just subtracting 10 from the DC and adding +1d20, and the PC is adding 10 to their modifier).

Oh, I see. Yeah, I probably wouldn’t use that technique for all passive checks, but I like it for when you want to determine an outcome secretly and want there to be multiple degrees of success/failure.

 

[Charlaquin]

Actually now that I think about it, if I were to use the semi-randomized DC idea, I might go with Easy = 5+2d4, Medium = 10+2d4, Hard = 15+2d4. That keeps the static element increasing by multiples of 5 at each step, and widens the possible range of DCs at a difficulty, but creates a bell-curve effect, so you’re more likely to get results closer to the average. And it puts the average on a whole number. I might try that with a small procedurally generated dungeon at some point.

 

[UngeheuerLich]

I have come to the conclusion, that passive perception is the old take 10. If there is no stress, passive perception is used. If you are in a hurry or under direct threats, you must roll.

 

[EzekielRaiden]

I have come to the conclusion, that passive perception is the old take 10. If there is no stress, passive perception is used. If you are in a hurry or under direct threats, you must roll.

Yes. That's pretty much exactly what it is.

 

[BookTenTiger]

I've started planning out next week's adventure using this system, and you know what? Something about it is really fun for me.

The secret door has a Perception DC +4. The trap has a Perception DC +6. The scorch marks on the door have a Perception DC +1.

Only during play will I, as the DM find out if they are going to be very easy to spot or a big surprise.

I can definitely see this not working for others! But I really enjoy creating systems that change the world as I run it in ways I cannot predict. I'll see how it goes during the session itself!

 

[DEFCON 1]

I also use the 'Passive Perception is the floor' method myself. And when setting DCs for things that are hidden I usually don't just assign them (thus having to worry about whether the number I assign will be automatically above or below the player's passive perceptions)... I instead roll a check for the person in the past who was setting or hiding the thing and their check creates the eventual DC that the characters will need to overcome.

So if there's a secret door in a house (like behind a bookshelf or whatever) then I'll roll a construction check for the person who built the secret door, and that check will end up the DC for the players to find it. Which is essentially creating a randomized DC, as others have also said they do.

 

[Maxperson]

Oh, I see. Yeah, I probably wouldn’t use that technique for all passive checks, but I like it for when you want to determine an outcome secretly and want there to be multiple degrees of success/failure.

I really like @BookTenTiger's idea, because I hate passive scores and this saves time. I can roll the passive bonus and compare to the Passive scores of the PCs, rather than have 4 players roll against a set DC.