[quote=@XxFellsingxX]
<Snipped quote by Vertigo>

I looked it up and it says it works like AC roll so... *shrugs* If I'm wrong, anyone can correct me.
[/quote]

I believe it really depends on how you imagine it. Since you're rolling Stealth and they're not actively rolling against you, you could call it a typical Stealth Skill check where the DC = the creature's Passive Perception. In this case, you just have to meet the DC in order to pass the check. Or, if you treat it like a contested skill check, then a tie means the situation remains unchanged. In the case of Stealth, that means the roller goes unnoticed I believe.

But I have often seen the "AC roll" argument used the other way around as well. Where the "Attacker wins the tie" rule is what you go to. And in the case of Perception vs. Stealth, Perception is usually what is considered the attacking roll since stealthing is inherently a defensive concept and trying to find a hidden target is considered an offensive act. So typically with this argument, the goal of a Perception check is just to MEET the defensive Stealth roll. Even with a Passive Perception, because all that basically means is that you're assuming the observer is just rolling a 10 on perception on average, rather than bog the game down with constant Perception checks.

But you could also see that last part being more in place for a player instead of an NPC since only players get tipped off to secrets if a Perception check is called.

So...long story short, it's totally open to DM interpretation, and I've actually seen it both ways before. xD I think I've usually played with "Perception is meet or beat Stealth" more often, so I assume that's the more common interpretation, but that doesn't mean the other isn't also just fine~

So yeah, however you want to roll with it should be fine! Heck, if you wanted to adjust it so that it always favors the player or always favors the NPC in terms of winning a tie because that sounds more fun to you, that's also a choice you can make~ xP