Does a PC know it rolled low when using stealth?

Question

This happens on a PBP session recently.

I have a goblin on a watch on a tower, but the party doesn't know this. This is an enemy base, so they rolled Dexterity (stealth) to get in.

One of the characters rolled low (9), and I noticed that they put "klank klank" sound in their in character action.

This makes me wonder, does a PC knows it rolled low when being stealthy? I know generally it does not, however in this case he failed because disadvantage of the heavy armor, so having the armor making a clanking sound seems appropriate.

Does this mean that PC knows he failed to move stealthily? If yes, this might have an unwanted ramification, like he stops and try to move stealthily again (or the whole party shush him) and let him roll for Dexterity (stealth) again.

My group does not have difficulty on keeping in character and meta knowledge out, if that is relevant, so if anyone asking for this, I don't know if this will be too meta or not.

Answer 1

Does a player know when they rolled low? Yes.

Does a PC know when they rolled low? Maybe.

Being stealthy is a combination of stuff: taking cover, moving slowly or quickly as appropriate, timing movement to avoid observation, being quiet, not tripping over the janitor's bucket etc. Similarly, detecting someone trying to be stealthy is a combination of stuff: looking in the right direction at the right time, hearing footsteps or breathing, smelling tobacco, actually paying attention to sensory cues etc.

For your situation, the goblin is going to detect the player, however, why they detect them is up to you to narrate. Because the low roll was caused by armor disadvantage its very cool to have the armor have something to do with it. Perhaps this isn't a continuous clank-clank-clank but maybe the armor causes a stumble which the goblin hears, or reflects the torchlight which the goblin sees or stinks of armor polish which the goblin smells.

Notwithstanding, the PC can't stop and try again, the action they attempted was sneaking into the camp: that's what prompted the stealth check. If they failed then the new circumstance is that they are detected and the game proceeds from there.

They may or may not know that they have been detected - that depends on if there actually is someone there to detect them and if the person who detected them revels that they have and if you decide that the thing that might have tipped off the observer is detectable to the PC. A gleam off the armor probably isn't, humorously tripping over a pile of spears which collapse with a loud clatter probably is. Feel free to mix them up.

However, a party attempting to use stealth together should be making a Group Check (PHB p.175) - this inherently accommodates those members of the party who are good at Stealth saying "Shhh". See Can stealth be consistently successful?

Answer 2

The character knows when they've failed a stealth check because something unstealthy has occurred, by which point it's obviously too late to go back and not do that.

There aren't two distinct actions involved. You don't make a stealth check and then enter the base -- your character can't, in some metaphysical way, attempt to "become stealthy", then look at themselves (as you roll a 1) and say, "Am I stealthy enough now? Oh, goodness, no, I'm not. I should not attempt this foolish course of action!"

You attempt to stealthily enter the base, which is a course of action that involves rolling a stealth check. If that attempt fails, the character becomes aware of that fact when the problem occurs -- they step on a twig, or their armor clanks at the wrong moment, or what-have-you.

From the player perspective, the die hitting the table is attempting the action, so they can't look at the result (even ignorant of what the difficulty may be) and then decide whether to proceed or not.