Modifying opposed skill checks

[Dr. Allard]

Hi!

I just started my first campaign as a DM, and naturally some questions came up after the first session.

One situation in perticular gave me a bit of trouble, how do opposed skill checks work if the circumstances are favourable/unfavourable for one part?

In this scenario, a guard was sitting behind a desk reading. A player wanted to sneak up to him, so I had him roll a stealth check. Then I compare it to the passive perception of the guard to see if he spots him.

My question is: how to I adjust the rolls to reflect the situation?

For instance: the guard is reading, and his passive perception should be lower than usual.

Also, the room was pretty brightly lit, and the sneaking player didnt come from a good angle, so his roll should also somehow be modified negatively to reflect that.

I cant find any information on this in the players handbook so any help would be greatly appreciated!

[MrStabby]

Use advantage/disadvantage.

In this case the room being brightly lit is the default (in dim light conditions sneaker gets advantage).

Use passive perception and modify the stealth roll.

[JellyPooga]

- If a check (opposed or otherwise) is favourable to a party, they get Advantage.

- If a check (opposed or otherwise) is unfavourable to a party, they get Disadvantage.

- Advantage/Disadvantage grant +/-5 on Passive Scores respectively.

Aaaand that's about the entirety of the rules on the subject.

[Dr. Allard]

Thanks for the answers! Missed it entirely. Since advantage/disadvantage is a pretty big bonus, I might just give a +2 or similar when there is a smaller advantage.

[MrStabby]

Well you do set the DC of the check which is effectively the same as applying a bonus or penalty.

The advantage/disadvantage thing has a further effect when it matters by how much you pass the check - say how much you tell people on a knowledge check. For some checks advantage vs +5 favours those who have a high chance of success, for others the opposite. It isn't neutral.

[Dr. Allard]

But you don't set a DC when it's an opposed roll correct? The DC is basically the opposed roll

[MrStabby]

But you don't set a DC when it's an opposed roll correct? The DC is basically the opposed roll

Yes, that's true. I was commenting on skill checks in general.

You need to work out if you want an opposed roll in each case. Opposed rolls tend to favour difficult checks (as an oversimplification one person rolling abnormally low OR the Other rolling high can cause an unexpected result - for only one person rolling you need a higher number on one die.

Stealth can be done against someone's passive perception, which is not an opposed roll - but what an opposed roll would be if the other d20 cam up 10.

In this case I would use a roll vs the passive perception of the person being sneaked upon.

[JackPhoenix]

But you don't set a DC when it's an opposed roll correct? The DC is basically the opposed roll

Your example in the OP uses passive perception, which is closer to a set DC than opposed roll. You can add arbitrary penalty (or bonus) to the guard's passive Perception score depending on how alert you want him to be.

[Dalebert]

In this case the room being brightly lit is the default (in dim light conditions sneaker gets advantage).

Technically the observer gets disadvantage from dim light (without darkvision), or -5 to passive perception. It matters more if there are multiple people to sneak by. Some might not be penalized depending on their senses.