I still would like to know what relevant portion of the DMG you are referring. I know of no such table for any kind of “mental circumstances” or anything close to what you’re describing. It sounds like homebrew stuff or confusion with some rules regarding psyonic abilities.

The big problem with twists like these…

If you know they’re coming, it sort of ruins the surprise. If the GM asks if it’s okay to have party betrayal (or if someone else asks and the GM says yes) then you’re constantly on the lookout for it - because why would they ask if it was irrelevant? Of course, nothing says the GM can’t ask an irrelevant question in the same manner they keep irrelevant minis next to their screen, but it’s something that’s usually frowned upon (what amounts to non-consensual PVP), so if it’s known to be ok, you’ll be looking out for it and then the twist won’t stick.

Of course, if you don’t know it’s coming, then it’s never a place your brain will go. You aren’t just going to accuse a character (and thus player) of working against the party because that’s a heavy accusation. It carries a lot of weight behind it since you’re only a few steps down from calling someone a problem player. Players often don’t have a good enough grasp on other players’ characters to notice behavioral shifts, and players often don’t have good enough acting skills to roleplay them correctly.

I’ve yet to hear a story where someone figured this kind of twist out before the reveal, and that doesn’t surprise me at all.

The multiple sections where it says the DM doesn’t control the PCs and describes the mechanics and reasons to roll skill checks in the first place.

Having a section describing how to do a contested roll isn’t the same thing as saying that is how you handle all player vs player skill checks, and it assumes you know that circumstances should affect the rolls beyond the numbers on your character sheet.

Tbf 5.0 is actually pretty bad about splitting up this information between the PHB and DMG, and assuming players have a better grasp of the whole picture than it should.

For example, in that Contested Roll section, it has this paragraph:

“Both participants in a contest make ability checks appropriate to their efforts. They apply all appropriate bonuses and penalties, but instead of comparing the total to a DC, they compare the totals of their two checks. The participant with the higher check total wins the contest. That character or monster either succeeds at the action or prevents the other one from succeeding.”

It assumes you know this has to be used with the sections describing things like environmental and attitude bonuses, and the sections on player agency and cooperative play, or for that matter NPC attitude tiers and how those specifically work with Deception and Persuasion, but it’s easy to gloss over that line and think it simply refers to a character stat line.

It also assumes you know that rolling that as contest was an option and not a requirement in the first place.

The DM isn’t controlling the players. The player of the paladin is choosing to use sense motive against my bluff checks.

Again, any circumstancial penalties or bonuses that are not inherent on your sheet are typically given by the DM. Such as you entering a room that has some kind of field or obstacle that imposes a penalty or confers a buff. It does not mean that a player can say “I have a super high iron will and so I get a +40 to any mind affecting spells!”

Not what I’m saying, and I know you don’t understand the problem, because you’re talking about spell save DCs which are not skill checks and are specifically under DM purview as a magical mind altering effect.

Think of it like this:

You have the right, as a player, to decide your character fucking hates someone so much they will not believe a word they say under any circumstance.

That would be, in terms of interpreting that to mechanics, setting the Skill DC to “impossible.” Which is ALWAYS AN OPTION FOR SKILL CHECKS. You can not jump to heaven with an Athletics check (normally speaking).

It could be you’re metagaming, but that’s a separate problem beyond the scope of skill, ability, and spell save checks.

Holy shit. No. I am not talking about spell save DCs; I am talking about circumstances that would provide a bonus or penalty that might not appear on your character sheet, using magical effects as an example.

Yes, you are, and you don’t know enough to know what you just said.

“I have a super high iron will and so I get a +40 to any mind affecting spells!”

Let’s use a different example then.

The characters have entered a room where the wind is absolutely howling, affecting their hearing, movement and balance. Anything they do in that room that requires a listen, movement or a balance check, has a -5 penalty. That is a circumstancial penalty.

The same can be done through magical means.

Sure.

And you as the player are the one who decides what the metaphorical wind is like for your character’s attitude towards the people and world around them.

Don’t trust the king? Good news, you can tell the DM that, and they can’t say “yes you do” unless you are affected by magic. They also can’t roll the king’s Persuasion to change your character’s mind about that without you agreeing to how the DC is set, including potentially a straight contested roll.

Or, to put it another way:

Just because they didn’t find a trap in the hallway doesn’t mean they have to think there isn’t one, especially if there’s a posted sign saying “This hallway is trapped.”

There is a difference between “you believe what they say” and “you can’t tell if they are lying.” The sense motive roll’s outcome only says whether or not they can tell if another character is lying; not even what the lie is or have anything to affect their personal belief. He might know the cleric is a bad guy; he just can’t prove it.

You could privately talk to your GM and say your character wants to cover all of their bases, so just like batman, spends time strategizing about how to defeat the other party members and making preparations in case they betray the group or him. Like a ring of concentration that also has an anti-magic curse activated when the correct word is spoken in its vicinity for the mage, secretly planted on the body of a mob that your character manages to get to before the party loots.

And then, of course, you’re in a position where you could betray the party and surprise even the GM.

Though a counter argument to what you’re saying is that deception games are a thing and the players knowing that there are enemies in the group doesn’t make those games trivial to figure out. A deception RPG could be interesting to play.

And he can think whatever the fuck he wants about that, which is entirely my point, because he, as a theoretically sentient being, is aware that he is flawed.

Unless there’s a character driven reason not to! Arrogance, naivete, backstory, whatever.

But, more pressingly, my point is to make you aware that there are more options available to the system for Deception checks than pure statblock measuring! And every table should be aware of that!

As well as the fact that Persuasion and Deception are not mind control.

Which I’m still not convinced you are, because this argument is still going.

As well as the fact that Persuasion and Deception are not mind control.

No fucking shit. I agree with that, my argument is that knowing the truth and believing it are two different things. It doesn’t affect their beliefs or motivations; it’s a god damn lie detector test.

At this point I can only come to two conclusions: You either don’t have a strong grasp of English or you are willfully not reading what I am saying.

And

A

Player

Can

Decide

They

Do

Not

Care

What

The

Lie

Detector

Says

Or

How

It’s

Calibrated

It’s a particularly interesting example you’ve chosen given that lie detectors are fucking pseudoscience and a specific character might not believe one single fucking thing they say

It could be, but it doesn’t have to be. It all depends on the characters involved.

The DM can referee in the dispute but they (usually) can’t say your character would or wouldn’t believe something.

A good DM might ask you to in-character justify your bias, for example. They’re also supposed to listen if you say “I don’t trust Count Fuckface on account of him having a history of being a Fuckface and also he’s standing over a cooling corpse with bloody hands.”

If a player is metagaming that’s a separate problem from their character being biased, or having a reasonably justified suspicion or whatever.

Or never, ever being interested in the creepy player’s character because they don’t like their vibes.

Every edition since at least 3.0.

In the sections describing how skills work and what circumstances you should allow checks for them, and the sections describing bonuses to those checks, what the role of the DMs and players are, including several very specific references to how character attitudes are very important to the DCs of those checks and the fact that skills only affect those attitudes in the first place and they aren’t mind control.

In other words, the whole fucking thing.