Out of Character Talk

I do not want to rule that passive perception is "always on" for 3 reasons:

First, I don't think it is RAW (rules as written) as nothing in the book says this. It very well might be RAI (rules as intended), but unless the book says something akin to "if you roll less than your passive, use that instead" then the rules don't actually say to do that.

Second, I think this comes from Jeremy crawford for the most part, but even he says "Passive checks are a tool for the DM. The DM decides whether the rule is used at all", meaning players were never meant to invoke the passive checks rule.

Third, I think is isn't the healthiest for the game to always use such a rule. I can see it making traps and secret doors use this rule if players would otherwise develop bad habits and become paranoid. I think It makes the most sense for stealth and perception to be active stealth versus passive perception to become or stay hidden and active perception versus passive or recent stealth to locate. However, for lots of other things, it creates the very feeling that was expressed. "I should have not even rolled." If the rule makes a player regret engaging with the game, it probably isn't good for the game. Bad rolls happen. I hate when I roll bad too. However, if the immediate feeling is regret in saying something, that seems wrong to me.

1. The thing is, Perception, Insight, and Investigation are all sensory-based skills. You don't turn those off. Barring a condition (blind or deaf, etc.) or unconsciousness, they are always active. Rules do sometimes create curious situations where they don't really work if taken RAW -- the Revivify spell being useless serves as a perfect example.

2. I mean, all rules exist at the whim of the GM. That's not really an argument in and of itself. And while players may not be intended to invoke the rule... if I spend an ASI to boost Wisdom, or take a feat/class level that grants expertise and choose Perception, or take a feat that improves passive perception (with no benefit to active), then as a player I have room to say I'd like my choices/investment to have some level of benefit.

3. I largely agree, especially with the feelings caused by the disconnect. However, there are ways to mitigate that feeling.

That said... the best answer (IMO) has been to acknowledge that sensory based skills are always on. It's arguably RAI, lets players feel their build does what it's meant to do, and keeps players from regretting engaging with the game.

1. Using the sensory argument is simulationist, which is a style of play some people like. It is simulationshist because it tries to take what happens in real life (the fact that we are always listening, even when asleep) and sees a concept like passive perception and says "if passive perception represents my non-active senses in action and my non-active senses are always working in real life then they are still working in the game because my character is a living creature like me". It's not a wrong way to play, but it is inferring. There are things we assume in game based on real life because the game can't cover everything. It is assumed you are breathing, even though the game doesn't say you are except in special situations. As for things like Revivify, I don't think it doesn't work RAW. There are rules interactions that aren't spelled out but working as written. The game doesn't say that if 2 blind people attack each other they roll normally instead of with disadvantage, but that is how it works. For Revivify, if someone died from level 6 exhaustion, and the just die immediately if revivified, that's not it now working, that's just a rules interaction that means if they died that way you shouldn't cast it on them.

2. I have experienced playing with someone who didn't rule a rule the same way as me because my interpretation of a rule RAW "didn't feel right to them" and so I'm familiar with the experience of when a DM makes something work differently than you are used to. I think this is an expectation situation, where we don't know we don't see things the same way or even think to ask and then it happens and we are surprised. I think this is something like illusions where depending on how important they are to you asking ahead of time is important.

3. I still argue that the fact that players might roll perception and then roll low and then regret rolling is a bigger disengagement in the game, as rolling is more active and just getting results makes the player more of an audience member than a player.

1A. Games require a great deal of inferring, because as you said they don't specifically point out every permutation. The idea that passive checks work in combat if someone takes the hide action, but not while you're walking down the street (or whatever)... is sort of ridiculous, IMO. (Worth noting, the fact the GM can choose to use them at any point for any situation they feel it best also implies they're "always on.")

1B. Revivify doesn't work if you go by RAW.

"You touch a creature that has died within the last minute."

The issue is, a dead body is not a creature. A corpse is an object. (Ruled by Crawford.) You can't cast Revivify on an object. The act of dying makes the body an invalid target for the spell, by RAW.

That said, it's painfully obvious what RAI is, and no one has issues running the spell as it is clearly intended to be used. But it does illustrate that RAW can create its own problems. (Because I don't believe for one second a third level spell was designed to be uncastable.)

2. I wholly agree, although I would submit that most cases of this are firmly because no one thought to ask, due to the huge amount of other info that was discussed/asked about.

3. I think that depends on how people build their characters. (Could also make a case for playstyle of course.) Still, if they're intentionally building a passive check... they probably understand what the "passive" aspect of it means.