self advantage vs target disadvantage

[n00b]

In the case of grappling is there any statistical difference between giving yourself advantage vs giving the target disadvantage on strength checks?

[Perlywhirly]

If they decide to escape with Acrobatics after you grapple them, disadvantage on Strength checks won’t be very helpful. Giving yourself advantage will help though!

[LudicSavant]

In the case of grappling is there any statistical difference between giving yourself advantage vs giving the target disadvantage on strength checks?

Enemies can opt out of using Strength.

[nickl_2000]

There is also cases where you get to re-roll on a certain result. For example, the halfling luck ability will apply even when you roll 2 die at advantage or the lucky feat.

[LibraryOgre]

And inflicting disadvantage on them might allow a save against the penalty, whereas giving yourself advantage likely will not.

[Unoriginal]

The enemy having disadvantage can be negated by them getting an advantage from something else.

[Max_Killjoy]

I think there's also some complicating math to consider, that depends on what each character's modifier to the roll is.

[Stoorn]

In the case of grappling is there any statistical difference between giving yourself advantage vs giving the target disadvantage on strength checks?

If you or someone else know a bit of programming you can use the following Octave code to simulate dice throws:


Awin=0; %dummy counter
Bwin=0;
Amodifier=0; %Player modifier
Bmodifier=0; %Enemy modifier

for i = 1:10000
A=randi ([1 20])+Amodifier; %edit here and get max(two random numbers) for advantage
B=randi ([1 20])+Bmodifier; %edit here and get min(two random numbers) for disadvantage

if A>B
Awin=Awin+1;
elseif B>A
Bwin=Bwin+1;
endif

endfor

WinRatio=Awin/(Bwin+Awin)




This code simulates 10000 dice throws and outputs ~0.5 for the current settings. I.e. player wins 50% of the grapple contests if both have 0 modifiers.

[n00b]

The reason I ask is I'm looking to make a grappler for a backup char and for some reason I don't want to play a Barbarian. I thought maybe a Rogue or Bard with a 1 level dip in Warlock for Hex might do the trick. Hex giving them the disadvantage I was speaking of.

[ShikomeKidoMi]

The reason I ask is I'm looking to make a grappler for a backup char and for some reason I don't want to play a Barbarian. I thought maybe a Rogue or Bard with a 1 level dip in Warlock for Hex might do the trick. Hex giving them the disadvantage I was speaking of.

Have you considered Variant Human Fighter with the Prodigy (Expertise with Athletics) feat? It might make wrestling up close and personal with people a little more survivable than Rogue or Bard (and if you want Hex you can just grab Magic Initiate, Variant Human fighters have so many feats), through a wrestling rogue that holds people in place and shanks them with a dagger is a pretty cool idea.

Anyway: The answer to your question vis a vis advantage/disadvantage is that both are good, they work out to roughly the same except in edge cases, and I think you'd mostly be fine without either as long as you have Expertise and a high strength.

[Chronos]

In a skill check contest between two characters, one of them having advantage is exactly equivalent to the other having disadvantage, no matter what the relative bonuses are. To prove it, let's first assume that player 1 has a modifier of +B (which might be negative) and advantage, while player 2 has a modifier of 0 and no advantage (because if both have bonuses, all that matters is the difference between their bonuses).

In other words, player 1 wins if the higher of two rolls of d20 + B is greater than one roll of d20.

Now take the negative of that: P1 wins if the lower of two rolls of -d20 -B is less than one roll of -d20.

Now add 21 to both sides: P1 wins if the lower of two rolls of (21-d20) -B is less than one roll of (21-d20).

But (21-d20) is exactly equivalent to d20: So P1 wins if the lower of two rolls of d20 -B is less than one roll of d20.

And finally, add B to both sides: P1 wins if the lower of two rolls of d20 is less than one roll of d20 +B.

But this last situation is just P1 rolling normally, and P2 rolling at disadvantage. QED.


Where differences come up is when one side or the other is able to change this dynamic. If, for instance, your opponent has a way to give themselves advantage, then your choice is actually between both rolls being normal (with the disadvantage you're imposing canceling out the opponent's advantage) or both rolls being at advantage (you giving it to yourself and your opponent giving it to themself). And these are not exactly equivalent: Compared to the normal rolls, both sides having advantage is slightly better for whichever character has the higher modifier.

Of course, the best of all, if you can get it, is advantage for yourself and disadvantage for your opponent. But this usually requires help from an ally, since most methods for doing either require concentration, or are inconsistent with concentration (like raging).

[Max_Killjoy]

In a skill check contest between two characters, one of them having advantage is exactly equivalent to the other having disadvantage, no matter what the relative bonuses are. To prove it, let's first assume that player 1 has a modifier of +B (which might be negative) and advantage, while player 2 has a modifier of 0 and no advantage (because if both have bonuses, all that matters is the difference between their bonuses).

In other words, player 1 wins if the higher of two rolls of d20 + B is greater than one roll of d20.

Now take the negative of that: P1 wins if the lower of two rolls of -d20 -B is less than one roll of -d20.

Now add 21 to both sides: P1 wins if the lower of two rolls of (21-d20) -B is less than one roll of (21-d20).

But (21-d20) is exactly equivalent to d20: So P1 wins if the lower of two rolls of d20 -B is less than one roll of d20.

And finally, add B to both sides: P1 wins if the lower of two rolls of d20 is less than one roll of d20 +B.

But this last situation is just P1 rolling normally, and P2 rolling at disadvantage. QED.




You're going to have to unpack that... why are we adding 21 to both sides?

[Chronos]

Well, we can add whatever we want to both sides. Me rolling with, say, +6 vs you rolling with +0 is exactly the same as me rolling with +1,000,006 to your +1,000,000. All we care about is which side is bigger.

The reason we're adding 21 specifically is because 21-d20 is just like rolling a d20: I have 1 chance in 20 to get a 1, 1 chance in 20 to get a 2, and so on up to 1 chance in 20 to get a 20. Which lets me turn that negative die roll into a positive die roll.

[Citan]

In the case of grappling is there any statistical difference between giving yourself advantage vs giving the target disadvantage on strength checks?
My gut says it all boils down to respective bonuses on each side.

If you both had the same bonus to STR checks, then it's a complete wash.
If you have a high bonus and it has a low bonus, then it may be worth imposing disadvantage.

You can check this very useful page that I keep close to me at all times. ;)
https://statmodeling.stat.columbia.edu/2014/07/12/dnd-5e-advantage-disadvantage-probability/
This should give you a nice idea of when one or the other may be better.

Truthfully though, I think the true use-case of imposing disadvantage is precisely to cut off options to the enemy by forcing it to use the lesser stat. Let's recall that when facing a Grapple/Shove attempt, any creature can freely choose whether to try escaping with an Athletics (STR) or Acrobatics (DEX) check. Obviously it will choose it's strongest proficiency.
Provided, of course, you know which is its forte and which is its weakest, imposing disadvantage through Hex on its forte may render it as unreliable overall as if using the weakest, or at least reduce chance to avoid to acceptable rate.

[Chronos]

No matter what the bonuses, you having advantage is exactly the same as them having disadvantage. I just mathed it out a couple of posts up there.

But the fact that, with grappling/shoving, the defender has a choice is one of those situations that can change things. If their good skill with disadvantage is still better than a regular roll of their bad skill, then it's still the same as you having advantage. But if a regular roll of their bad skill is better than disadvantage with their good skill (which it very often will be), then that's a situation where giving yourself advantage is better. Look at the extreme case: If both of the defender's skills are equally good, then obviously they're going to choose whichever one you didn't give disadvantage to, and it's going to be as if you didn't even give them disadvantage at all.

[Provo]

There is one difference. If you impose disadvantage, you can cancel any advantage that they have. So in some cases, this is the difference between two opponents using straight rolls or two opponents rolling with advantage.

Considering that you are building as a grappeler, you will have higher athletics than most of your enemies. It would be preferable for both of you to have advantage then both of you doing straight tools in that case.

So to buff yourself would be better in such a case.

[Citan]

No matter what the bonuses, you having advantage is exactly the same as them having disadvantage. I just mathed it out a couple of posts up there.

But the fact that, with grappling/shoving, the defender has a choice is one of those situations that can change things. If their good skill with disadvantage is still better than a regular roll of their bad skill, then it's still the same as you having advantage. But if a regular roll of their bad skill is better than disadvantage with their good skill (which it very often will be), then that's a situation where giving yourself advantage is better. Look at the extreme case: If both of the defender's skills are equally good, then obviously they're going to choose whichever one you didn't give disadvantage to, and it's going to be as if you didn't even give them disadvantage at all.
Nice way to contradict yourself from first paragraph to the next. :)

Also, your demonstration does not hold anything. Confer the link I put.
It's the same only when respective bonus to roll are the same, otherwise it's different simply because the minimum/maximum roll each can get is different which in cascade implies a different alteration of chance with disadvantage or advantage.
So it's not the same overall. And that's exactly what you just stressed in your paragraph.

[Unavenger]

So, you succeed wherever 2d20b1-1d20 or 1d20-2d20w1 is greater than a target number which is functionally (their bonus - your bonus). The distribution of 2d20b1-1d20 and 1d20-2d20w1 are the (https://anydice.com/program/135aa) same (https://anydice.com/program/135ab).

This only applies, mind you, if they're always going to be trying to use their strength, even at a disadvantage.

[Chronos]

I'm not contradicting myself. My first paragraph says that player 1 at advantage vs. player 2 at normal is identical to player 1 at normal vs. player 2 at disadvantage. My second paragraph points out that that's not always the relevant comparison.