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Old 01-15-2018, 10:55 AM   #1
myrmidon
 
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Default Perception Modifiers for Stealth vs. Perception Check

When doing a Stealth vs Perception check, do modifiers such as lighting or distance get applied to Perception? Or is it just a straight contest? Does lighting give a bonus to Stealth? I assume lighting would not apply to both Stealth and Perception in the same contest, as that would be double-counting it.

The particular situation of which I am thinking is a PC standing in a dim hallway and trying to spot an NPC hiding and peeking around the edge of a corner to look at the PC.
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Old 01-15-2018, 10:59 AM   #2
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Default Re: Perception Modifiers for Stealth vs. Perception Check

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Originally Posted by myrmidon View Post
When doing a Stealth vs Perception check, do modifiers such as lighting or distance get applied to Perception? Or is it just a straight contest? Does lighting give a bonus to Stealth? I assume lighting would not apply to both Stealth and Perception in the same contest, as that would be double-counting it.
In general, if the Stealth is being opposed in a Quick Contest (against Perception or Observation), penalties for vision like lighting or distance do apply, and they apply against the watcher's Perception skill. Note that not all Stealth rolls are opposed, though - in general, I only call for opposed rolls when someone is actively looking for the stealthy character: an alert sentry, a mechanical device that's constantly scanning, and so forth. If they're not alert, then the Stealth roll is unopposed, and any penalties for vision on the part of the watchers then apply as bonuses to the sneaker's Stealth roll instead.
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Old 01-15-2018, 11:23 AM   #3
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Default Re: Perception Modifiers for Stealth vs. Perception Check

Realistically, although poor visibility helps Stealthy Sue more than Perceptive Pete in such an example, I still think that Stealth should be somewhat harder for a character who can't see. If she can see no better in the darkness than Perceptive Pete, Stealthy Sue risks stepping on lurking Legos, slipping on an unseen wet/icy patch or walking boldly into a table. Even if she can mostly see her surroundings, she won't be able to pick a route that minimises all noise and exposes her to minimal time in the potential line of sight of any hostiles as well as she could were she better able to observe minute details of the terrain (or flooring).

As a houserule, I might penalise Stealthy Sue by half the effective darkness penalty, ruling that as she's moving slowly and feeling her way, she is not totally reliant on Vision, but she's still missing an important sense. Perceptive Pete gets the whole darkness penalty to his attempt to spot Stealthy Sue.

Of course, he's not at any penalty to hear her. Which, granted, will usually only allow detection of someone sneaking close by.

As for the range penalties, I'm not certain myself. Due to Visual, Auditory, Olfactory and all other basic mammalian senses being abstracted into one QC roll against Stealth, I'm not always sure at what distance one should use unmodified QC and at which distances Stealthy Sue or Perceptive Pete ought to be at relative advantages.
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Last edited by Icelander; 01-15-2018 at 11:32 AM.
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Old 01-15-2018, 12:33 PM   #4
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Default Re: Perception Modifiers for Stealth vs. Perception Check

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Originally Posted by Icelander View Post
As for the range penalties, I'm not certain myself. Due to Visual, Auditory, Olfactory and all other basic mammalian senses being abstracted into one QC roll against Stealth, I'm not always sure at what distance one should use unmodified QC and at which distances Stealthy Sue or Perceptive Pete ought to be at relative advantages.
I only penalize hearing if the target is really pretty far away (it's roughly -1 per 5 yards as a house rule)... but I do add Ambient Noise penalties. Lot's of Ambient Noise penalties...

In this case I have the QC rolled and don't announce any penalties. I then apply the penalties to the results and determine outcomes from there. So if Perceptive Pete would have failed to see Stealthy Sue, he doesn't see her, but if he could have heard her, Pete's Player is told that Pete heard something, and if he succeeded by enough*, even the direction (and if he really won by enough**, what type of sound it was).


* No hard fast rule, but I like it as a "if you beat the Hearing roll by twice the range penalty" kinda thing. Sometimes (if the noise is loud enough to give a bonus) I don't bother with 'beat by so much' and just give it to them.

** This one really falls into a GM call thing, but I tend to like "by 5 or more".

Last edited by evileeyore; 01-15-2018 at 12:36 PM.
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Old 01-15-2018, 01:13 PM   #5
vicky_molokh
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Default Re: Perception Modifiers for Stealth vs. Perception Check

Here are some Krommquotes on the various modifiers to Stealth and detection.
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Old 01-15-2018, 02:06 PM   #6
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Default Re: Perception Modifiers for Stealth vs. Perception Check

That answers my questions. Thank you all very much.
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