Hark! A Swallow!

Welcome to the third installment of Everyman Gaming’s GM’s Guide articles. In this GM’s Guide, we’ll be talking about proper use of the Perception skill.

One of the common complaints that I see on the forums is in regards to the Stealth skill. Specifically, in regards to how the Stealth skill interacts while hiding from others. Many people complain that the Stealth skill needs better language but honestly, I think that Stealth is just fine the way it is. However that can’t be said for its opposed skill, Perception.

This week on Everyman Gaming, we’re going to be looking at the opposition between the Stealth skill and the Perception skill. Specifically, how can you as the GM use these skills to determine just how and when your enemies see your PCs and vice versa.

Kenebras – An Anecdote

So this anecdote continues minor Wrath of the Righteous spoilers. You’ve been warned.

So a few weeks ago my party is trekking through Kenebras in Paizo’s Adventure Path, the Worldwound Incursion when my PC, Yansu, suddenly gets the feeling that the party’s being stalked. I was the only person who say the monster, a Howler, and based on the results of my comrades I only just barely made the Perception skill check.

“How far away is the howler?” I ask.

“200 feet,” the GM replies.

“So let me get this straight,” I asked. “This monster is 200 feet away from us and I heard it with a 25 but Gibbenzgob didn’t hear it with a 22?”

“Yup,” my GM replies.

Doesn’t That Seem Peculiar?

Raise your hand if you’ve ever done something like this before: select a somewhat random, arbitrary distance for your monster to be from your PCs when they succeed on a Perception skill check to notice an opponent who is attempting to skulk about using the Stealth skill. I know I’ve done it before, but quite frankly folks there are rules in the game that makes this practice utterly impossible: Perception modifiers.

If you go into Chapter 5 of the Core Rulebook, you’ll notice that there are roughly three tables of modifiers for the Perception skill. One of them is a distance modifier. The distance modifier for Perception is extremely easy: the DC for a Perception skill check increases by +1 for every 10 feet between a character and the source, creature, or object that is being detected. As a matter of fact, most of the Perception modifiers are wildly underused in most campaigns: they serve to check the power of the Stealth skill and Perception skill. And how might they do that, you ask? Well, just ask yourself: what is the DC of a Perception skill check made to notice a sneaking creature? The answer?

The sneaking creature’s opposed Stealth skill check is the DC of the Perception skill check, of course.

Determining Distance from a Hidden Foe

So, how can we use this rule to determine how far away from its mark a wild creature is? Its actually very simple mathematically: subtract the Stealth skill check result from the Perception skill check result and multiply the result by 10 feet to determine how far away an opponent is when your PC detects it. (Or vice versa.)

Let’s use mathematics to demonstrate. Let’s say that Yansu, my kitsune bellflower tiller, rolls a modified 25 on his Perception skill check to detect a nearby howler as it creeps in towards him. The howler rolled a 25 on its Stealth skill check.

  • 25 (Perception) – 25 (Stealth) = 0. 0 * 10 = 0 feet. Yansu does not detect the howler until it is adjacent to him. Why? The distance rule noted above gives the howler bonuses the further from Yansu that it stays.
  • For example, when the Howler is 10 feet from Yansu, the DC for Yansu to detect the howler increases by +1; effectively, its Stealth skill check is now a 26 compared to Yansu’s 25. When the howler is 20 feet away, it has a 27. From 30 feet away it has a 28, and so on.

Here’s another example: Let’s say that Yansu still rolls a modified 25 on his Perception skill check to detect the howler. This time, the howler rolls a 20.

  • 25 (Perception) – 20 (Stealth) = 5. 5 * 10 = 50 feet. Yansu does not detect the howler until it is 50 feet away. Why? Well, when the howler is 60 feet away, the DC of Yansu’s Perception skill check gains a +6 bonus, meaning that the howler has an effective Stealth skill check of 26. As soon as it moves to 55 feet away, however, Yansu is able to detect it because this Perception DC modifier drops to a +5, in which case Yansu’s result of a 25 is enough to detect the howler.

As you can see, using the Perception skill modifiers to calculate an opponent’s distance from the PCs (or vice versa) when the combat begins is extremely easy and is heavily supported by the rules.

Additional Modifiers

Of course, there are oodles of additional modifiers that should be used when using Perception. For example, any favorable or unfavorable conditions that are present (such as bright light or a distracting odor) may increase the DC. Sometimes these conditions might double dip in either party’s favor: for example, a flat plains is unfavorable for using Stealth but favorable for using Perception while a dense, dark wood is unfavorable for using Perception but favorable for using Stealth. Its important to make sure that these modifiers are noted, because if you’re not you’re probably making things needlessly easy for the PCs (if they are using Perception) or needlessly challenging for the PCs (if they are using Stealth).

Sniping and Perception

Its important to note that sniping isn’t as hard as it seems. At least, its not if you’ve got plenty of distance like a good sniper should. For those who do not know, sniping incurs a –20 penalty on Stealth skill checks made to hide after using Stealth. But with the right weapon, this isn’t really a big deal. Let’s watch.

Roik is an archer who uses a longbow (range increment of 100 ft.). He sees a particularly powerful demon about 200 feet away that he knows he might not be able to hit on his own. As a slayer, he marks the demon as his favored target, gets behind some cover, and snipes. After sneak attacking his foe, Roik rolls a 25 on his Stealth skill check. The demon rolls a 24 on his Perception skill check.

  • First, let’s look at the modifiers. Roik is receiving a –20 penalty on his Stealth skill check to hide because he is sniping. This means that Roik has an effective Stealth result of a 5.
  • That said, the demon is 200 feet away. As a result, the DC of its Perception skill check to notice Roik increases by +1 for every 10 feet that the target of his Perception skill check (Roik) is from him. That’s a +20 to the Perception skill check DC, which is Roik’s opposed Stealth check.
  • In effect, Roik is able to cancel out the penalty for snipping by being 200 feet away from his target. In all, he only suffers a –2 penalty on his longbow’s attack roll because his target is within his longbow’s second range increment.
  • 24 (Perception) – 25 (Stealth) = –1. -1 x 10 = –10 feet. If Roik had been 10 feet closer to the demon, he would have been noticed and the Stealth skill check would have failed. But he wasn’t, so it didn’t.

So basically, if you want to snipe use a longbow. A shortbow might be okay, but longbows are better.

Wrap Up

So, in conclusion Stealth works fine the way it is. The only real “change” that you need to make in regards to Stealth is how you view the result. That, and making sure to count all of the odd little Perception skill modifiers that should be going on with a given Stealth skill check roll. To keep track of these, you might want to consider jotting the table onto a note card or something. I think that the tables are also reprinted on Paizo’s GM Screen product, but I don’t want to 100% say for sure that they are definitely there in case I’m wrong. Horribly wrong.

And that’s all I have to say about Stealth. For now, at least. What do you think? Did I cover all of the major concerns with Stealth skill checks or are there still plenty of arguments for me to exploit in a future article? How do you handle Stealth skill checks in your game? Do you remember to use Perception modifiers? Are you guilty of just plopping down monsters and PCs wherever you feel like placing them when a successful Perception skill check is made? Leave your answers below and I look forward to hearing from you soon. Until then, adieu to you!

Alexander “Alex” Augunas has been playing roleplaying games since 2007, which isn’t nearly as long over 90% of his colleagues. Affectionately called a “budding game designer” by his partner at Radiance House, Alexander is the author of the Pact Magic Unbound series (Radiance House) and a handful of other Third-Party Products. Before founding the Everyman Gaming blog, Alexander gained notoriety for writing the GM’s Guide to Challenging Encounters, which remains accessible to this day. His favorite color is blue, his favorite Pathfinder Race/Class combination is kitsune master spy, and he has never actually gotten to implement any of the advice listed in this blog in one of his own games. How unfortunate.


3 thoughts on “Hark! A Swallow!

  1. I absolutely use Perception modifiers in my game, and it annoys the hell out of my players when I do. The only other big issue is that, once combat starts, technically, you are unable to get sneak attacks at range because the target is no longer flat-footed; at least that’s one argument people make.

    Personally, I couldn’t care less. If you make your stealth check, then you get sneak attack, period.

  2. Or the GM didn’t explain the situation fully– maybe the howler was making some small noises without actively trying to be stealthy, so he applied the distance modifier with the skill bonus and subtracted a small circumstance penalty for the small noises, resulting in a 24 DC? That’s certainly a reasonable series of decisions, especially if the GM wanted to create tension by stalking group at range–whether or not he succeeded is another question.

    My point is that there’s plenty that can go into creating a situation’s DC. Unless you set the DC, the anecdote is missing crucial aspects.

  3. Thanks for this. It’s great, and remarkably simple when broken down this way. I’m guilty of doing hand-waving when it comes to how close an encounter starts, so I can change this.

    I can tell you that the GM screen does indeed have the tables for DCs (and modifiers) around Perception. So… yeah.

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