D&D 5E Which is better? Quick Maths help request

[rgoodbb]

For a 10th level Warlock with Mask of Many Faces, which is most optimal:

Expertise in Deception totalling +12

Or

Deception of +8 with Advantage.

I’m looking at the Actor Feat and the SilverTongued UA Feat and my maths skills are just horrendous. Luckily I belong to a fantastic community most of whose skills are easily far better than mine.

Many thanks in advance.

 

[Jaelommiss]

It depends on the DC you're up against. For up to a DC of 14 you're better with +12. From 15-23 you're better off with +8 and advantage. For 24 and up +12 is better again.

You can see this in action here. Select Graph for View, and At Least for Data. The x-axis is the DC. The y-axis is the probability of hitting that DC. The higher the line at any one place along the x-axis, the greater the probability of hitting that DC.

In practice they are both going to be very similar. +12 has a mean result of 22.5. +8 with adv. has a mean result of 21.82. Having advantage reduces standard deviation, which is fancy talk for saying that the most likely result occurs in a smaller range. Specifically, results from 1-5 on the d20 become significantly less likely, and higher results become increasingly more likely. The difference between the probabilities of hitting any given DC is less than 10% all the way up to DC 25.

From a DM design perspective, I would rather give the player +12 than permanent advantage. This allows the DM to apply adv/dis as is appropriate to the situation. The DM could adjust and give the player a numerical bonus or penalty for the situation, but it's more work than using the default advantage system.

Looking forward, if the character's proficiency bonus increases by 1 then the situation changes to +14 vs +9 w/ adv. In this case having +14 beats +9 w/ adv. for every single DC from 15 to 34. At the closest, +9 w/ adv. gets to 0.25% for a DC of 21. It is increasingly worse the further you get from that DC. Except at the fringes it's still fairly close, but this is a situation that will be amplified with every increase in proficiency bonus. For every +1 to proficiency bonus, the character with expertise will increase their mean result by 2, whereas someone with adv. but not expertise will increase their mean by one. The character with expertise will also increase the minimum and maximum results they can achieve faster than the character without. Using adv. instead of expertise could preserve bounded accuracy.

 

[TaranTheWanderer]

Expertise. You can get advantage in other ways and still have a +12

 

[FrogReaver]

Forget the bonuses. I’d suggest actor just because being able to sound like anyone is very useful and fun.

but if you are just looking at the best bonus silver tongued is better. It works on all deception checks where actor is limited to a certain smaller subset

 

[Henry]

It depends on the DC you're up against. For up to a DC of 14 you're better with +12. From 15-23 you're better off with +8 and advantage. For 24 and up +12 is better again.

I have nothing to add, other than "thank you for introducing me to anydice.com" !

 

[rgoodbb]

Hmm. I could have them both but then only an 18 in Charisma instead of a 20. Seems expensive.

I will think more upon it. Cheers for your thoughts and Expertise in Maths.

 

[clearstream]

For a 10th level Warlock with Mask of Many Faces, which is most optimal:

Expertise in Deception totalling +12

Or

Deception of +8 with Advantage.

I’m looking at the Actor Feat and the SilverTongued UA Feat and my maths skills are just horrendous. Luckily I belong to a fantastic community most of whose skills are easily far better than mine.

Many thanks in advance.

Assume opponent passive Wisdom (Insight) scores are in the range 10 to 19 and most checks are Contests. The nuance is this.

+12 needs -1 to 8. Which is from 0% chance to fail to 35% chance to fail.

+8 with advantage, needs 3 to 12. Advantage means at the easy end only 1% chance to fail. Or at the hard end ~30% chance to fail.

On the other hand, +12 can make a Nearly Impossible DC while +8 can only make Very Hard. Further, +12 can't possibly fail some checks that +8 can fail, even if it is quite unlikely to.

All that is before Bardic Inspiration or Guidance. If I had Guidance, such as through a Tome pact, I would probably prefer +8 with advantage. Otherwise +12.


[EDIT I see someone above points out what happens for each proficiency gained. I agree Expertise looks better that way... but then proficiency is pretty slowly gained...]

 

[ccs]

Hmm. I could have them both but then only an 18 in Charisma instead of a 20. Seems expensive.

I will think more upon it. Cheers for your thoughts and Expertise in Maths.

Then take them both.
I'm sure you get more features with both than you would with only one or the other & an extra +1 cha bonus.

And if you've (mathmatically) made a character that falls apart because of the lack of a single +1?
Then you've made a bad character.

 

[Keravath]

Keep in mind that expertise will continue to go up with levels while advantage will not.
At level 10 it is +12 vs +8 with advantage.
At level 13 it is +14 vs +9 with advantage.
At level 17 it is +16 vs +10 with advantage.

At your current level there is a band of DC's from 15 to 23 where advantage is slightly better
At 13-16th level, there is one DC where they are equal.
At 17th level+ expertise is strictly better at achieving any specific DC.

e.g. Lets say at level 17 the DC was 30 ... which is the maximum possible DC achievable by a +10 skill. Advantage gives a 9.75% chance of success while the +16 modifier only needs to roll a 14 or more which is a 35% chance of success.

A table showing probability of rolling greater than or equal to the number you need to roll to succeed (i.e. DC minus skill) with a straight roll, advantage, disadvantage etc. is http://www.enworld.org/forum/showthread.php?654979-The-math-of-Advantage-and-Disadvantage

 

[Blue]

+12. The numbers are close either way, but +12 means that you can reach DCs up to 32, while with +8 and advantage you can only reach DCs up to 28. Plus you can get advantage other ways, to make the +12 even stronger.