Listen/Spot Rules Suggestion

[WalkerWhite]

I am interested in getting some feedback on this rule idea. The problem has to do with the fact that there are two passive skills for detecting stealth characters: Listen and Spot. These correspond to the two stealth skills: Move Silently and Hide, respectively. The result is that guards have a huge advantage.

Suppose we have a guard and a rogue. Both have equal ranks in Listen/MS and Spot/Hide. First, let's just look at one of those pairings: Spot/Hide. The active skill, Hide, sets the DC. So, given the discretization of the d20, that means the passive skill Spot gets a 2.5% advantage for ties. Hence the probability that the guard succeeds in his Spot check is 52.5%

However, if we just want to know whether the guard detected the rogue, the probability changes. The guard only has to succeed on one of the two skills. Therefore, the probability is

52.5% + 47.5% * 52.5% = 77.4375%

This is a huge advantage, considering that they have equal ranks.

Our group has been talking about how to handle this. Some people claim that this is not too bad, since Listen does not reveal too much information; however, you do not need to be pinpointed for the guard to call an alarm. Others suggest that we make Listen only an active skill; but this prevents having interesting things like guards that can only Listen, not Spot. Still others argue that we should combine the two for abstraction purposes, even though they clearly do different things.

I want to preserve both skills, but eliminate the huge advantage. So my suggestion is to do something like two-weapon fighting. Every creature favors one of the two skills. Humanoids favor Spot, while many animals favor Listen (and a player may choose which one his character favors). If both are being used simultaneously, then there is a minor penalty (-2) to the favored skill, and more (-4) to the unfavored one. A character can concentrate exclusively on one of the two skills for no penalty on the favored and a major penalty (-10) to the unfavored one.

Let's say our guard favors Spot, but is using Listen as well. We give him a -2 to Spot and -4 to Listen. Then, his advantage on the rogue is

42.5% + 57.5% * 22.5% = 55.4375%

which is pretty close to a single skill. Now suppose that the guard only managed to hear the rogue, and he wants to find exactly where he is. He then concentrates exclusively on Spot for no penalty, but gets a -10 to Listen. Then his probability on getting any more information is

52.5% + 47.5% * 2.5% = 53.6875%

This is less than before, but the guard has more control on which skill picks up the rogue.

Comments?

 

[DaveStebbins]

I thought the mechanic was that the DM determined which of the two skills applied the most and use that opposed check to determine the outcome. If the thief is primarily hiding, use hide/spot; if the rogue is moving, use move/listen. Decide on a case-by-case basis.

3.0 DMG, page 91 (sections on skill checks, subsection on sneaking) says its a judgement call by the DM. Sometimes two checks are called for, sometimes just one.

Finally, my gut feel is that guards will have a much smaller bonus for spot and listen than an equal-level rogue will have in hide and move.

-Dave
[edit - added second and third paragraphs after looking the situation up]

 

[AeroDm]

I always called for both checks to be rolled and figured it was "equal" because the people who choose to sneak are generally very good at it while spot/listen is relatively exclusive on skill lists.

However, after seeing AU and the use of Sneak, I began to reconsider. The more I think about it one skill (perhaps Sense or Perception) sort of does make more sense (I tried not to make the pun, but I am on 3 hours of sleep and couldn't figure anything else out).

If you want the unique scenarios of guards who can only listen, I don't really see why this couldnt be implemented with just one skill and flavor text. YMMV, hope that helped at least a little.

 

[Spyritwind]

Just make one dice roll instead of two. Example:

Syris the rogue is sneaking up on a bug bear gaurding the front of a cave. Syris has +10 with move silent and a +10 with hide. Syris will try to stay in the shadows along the face of the ridge as best he can, but the DM decides that the torch on a pole will still create a less than perfect environment for Syris especially since he is moving instead of remaining still and will give Syris a -2 to his hide skill.

Syris rolls a D20 and gets a 7.

7+10 for moving silent ='s 17 &
7+10-2 for hiding ='s 15

The bug bear has a plus 6 in spot and plus 2 in listen. The DM rolls a 12 for the bugbear giving him an 18 for spot and a 14 for listen.

The bugbear 'spots' Syris, but he didn't hear him coming.

Just roll once instead of twice. The idea is that Syris wants to be undetected and the bugbear wants to detect. The possible varience in bonus between the skills and other modifiers will still be a factor though.

 

[iwatt]

By the way, your analysis is totally negelecting the fact that 10' means a -1 to the check. Assuming your character wants to sneak up to 30' (partial charge distance for a medium sized rogue), he's gotten a big enough break (i.e the guard only hears him 38,25% of the time and only sees him 38,25% of the time). But as you say, the guard only need to detect him through one of his senses. The possible outcomes are:

H=Heard NH=Not Heard S=Seen NS=Not seen

H-S 38,25%x38,25% =14.63%
NH-S (100%-38,25%)x38,25% =23.62%
H-NS 38.25%x(100%-38,25%) =23.62%
NH-NS (100%-38,25%)^2 =38.13%

So he's detected 61.87% of the time (pretty high actually). But this is assuming equally skilled sneaks v/s guards. Also, been heard is not nearly as terrible as been seen, as was mentioned before. Most guards will have the alertness feat, maybe a Wis 12, and maxed cross rank skill in listen and spot (unless a rogue or ranger himself). The average sneaky rogue will have Dex 16, no Armor Check penalty, and maxed out skills. The alertness feat defeats the ability modifier difference, and most rogues wont take Stealthy as a feat (better uses for feats). So if both the Guard and the Rogue are same level (X), then the ranger is up in the game by: (X+3)/2
i.e.
Level 1
Guard 2(ranks)+1(Wis)+2(Alertness)= +5
Rogue 4(ranks)+3(dex)= +7
He's detected at 30' 51%

Level 5
Guard 4(ranks)+1(Wis)+2(Alertness)= +7
Rogue 8(ranks)+3(dex)= +11
He's detected at 30' 45%

Level 9
Guard 6(ranks)+1(Wis)+2(Alertness)= +9
Rogue 12(ranks)+3(dex)= +15
He's detected at 30' 35%

These are pretty high detecting chances, but remember this is scenario in which the guard is quite capable.

By the way, in d20 Modern you can even get hide modfiier from cover (+5 for 3/4; +10 for 9/10),so this also aids the sneaker even more. Although in [3.5] ther's no more varied levels of cover I think, so I don't think you can use this.

Maybe all these numbers helped you see that it really isn't impossible to sneak, although it is increasingly hard to sneak "very" close.

 

[Li Shenron]

I think that a quite good DM is better than any house rule... Don't be too rigid assuming that every guard which succeeds in a Listen check also discerns what the noise is. And a guard that every noise calls for an alarm is not lasting long in his duty.

It's true that distance penalties are ofter overlooked, while they are very important in many situations, as other circumstance penalties that can become a big advantage to the stealth character. I am not sure, but I think that an example check with no modifier would be someone sneaking in sunlight and mostly silent environment 5ft behind the guard; shadows or darkness and a little more than natural noise already provide significant bonus. (i am not looking at the DMG now, but i think it mkaes sense...)

In some situations, the DM still rules that only 1 of the two skills apply.