Would you rather have Expertise or Advantage on a roll?

BookBarbarian · Apr 17, 2018

The Old Crow said:
Expertise.

Why? Because if I don't have Advantage, it is still possible to also create Advantage, but if I don't have Expertise, nothing will get me Expertise.

This is precisely how I feel.

Sunseeker · Apr 17, 2018

Expertise, hands down, every time.

FrogReaver · Apr 17, 2018

I tend to agree that it's better to get expertise because of advantage but it's also worth noting that advantage is pretty solidly better than expertise against most DC's and by magnitude before level 13.

For example at level 4 when comparing to DC's 10-25 Advantage is better against 9 of the DC's between the equivalent of +2 to +3 (14.75 highest). The only DC expertise fares better on is DC 25.

For example at level 8 when comparing to DC's 10-25 Advantage is better against 9 of the DC's between the equivalent of +1 to +2 (10% highest). There are 3 DC's expertise fares better on and it's not even better on those by the equivalent of +1 (5%). (+2.25% is the highest).

Level 9 gets much closer but is still slightly in the favor of Advantage.

Level 13 is when expertise becomes clearly better and even then it's only a slight amount better... by about +1 in the best case (+6.25% to be exact)

Level 17 is when expertise becomes clearly much better than advantage

So I'd rather have advantage if it wasn't easy to get it through allies helping you. There's many skill checks that DM's are reluctant to give out easy help advantage for. On those I'd rather have advantage if I could choose. If it's something I can just about bank on an ally being able to help me with then I'd rather have expertise. If I started level 13+ I'd rather have expertise. Otherwise I'd much rather have advantage.

Mercule · Apr 18, 2018

Slit518 said:
Advantage -
If I am not mistaken it is determined Advantage is the equivalent of a +5 to the roll, unless the math on that has changed.

It actually depends on the target number. It's been a while since I ran the numbers, so I may be a bit off but the gist is that advantage gets better as the target number approaches 11 and worse as it approaches either end of the spectrum. Why? Just because of the way odds multiply.

At a target of 11, you're essentially at a coin flip. That means that you've got a 50% chance of even caring about the second roll. If you do, it's a 50% chance of helping you. That means .5 + (.5 * .5) = .75. So, at a target of 11, you get an extra 25% chance of success, which is the same as a +5 to a d20.

At a target of 20, you'll want that second roll 95% of the time, but it only helps 5% of that 95%, which is 4.75% (.95 * .05) improvement. That's close enough to 5% to just call it good. So, at a 20 target number, advantage is marginally inferior to a +1.

Things get a bit weird to translate to bonuses, as you approach a 1 target. At target number 1, advantage turns a 5% chance of failure to a 0.25% chance, which is the same variance from an actual +1 as with a 20 target number, but I find it less easy to dismiss. Regardless, while the curve isn't identical on both ends, it's close enough for rough in.

Worth noting is that, at 5 and 15, advantage is worth a bit less than a +4 bonus. Depending on how tough your group tends to run with DCs and armor, that's a sizable chunk of DCs that are covered by that bonus. Personally, I'd consider it on par with a +3 constant bonus, which means a break even for character levels 5-8 and advantage being better beyond that.

BookBarbarian · Apr 18, 2018

This makes me miss the Fighter Scout from Unearthed Arcana. It had a neat way to boost certain Ability Shecks that wasn't Expertise or Advantage.

Leatherhead · Apr 18, 2018

Here is some math for you.

For the TL;DR crowd:
Expertise is better for Low DC checks.
Expertise is better for High DC checks.
Expertise has better probability for most extreme situations at level 9
Expertise has better or equal probability in every situation at level 13.
Expertise has better probability in all situations at level 17.
However, Advantage does have it's upsides:
"15ish" is the common target number for most tasks (which isn't outpaced until Expertise gains a +5 bonus)
It lets you crit twice as often.
It totally negates any form of Disadvantage (which has a way nastier impact than even a -4 penalty to your attack roll)

This leads me to the following conclusions:
If, for some reason, getting one meant never getting the other. Then I would have to go with Advantage, as I almost never get to play level 17+ characters anyway.
If you can still get both, I would rather start off with Expertise, because Advantage is way easier to attain.

FrogReaver · Apr 19, 2018

Leatherhead said:
Here is some math for you.

For the TL;DR crowd:
Expertise is better for Low DC checks.
Expertise is better for High DC checks.
Expertise has better probability for most extreme situations at level 9
Expertise has better or equal probability in every situation at level 13.
Expertise has better probability in all situations at level 17.
However, Advantage does have it's upsides:
"15ish" is the common target number for most tasks (which isn't outpaced until Expertise gains a +5 bonus)
It lets you crit twice as often.
It totally negates any form of Disadvantage (which has a way nastier impact than even a -4 penalty to your attack roll)

This leads me to the following conclusions:
If, for some reason, getting one meant never getting the other. Then I would have to go with Advantage, as I almost never get to play level 17+ characters anyway.
If you can still get both, I would rather start off with Expertise, because Advantage is way easier to attain.

#1 It would help if you defined Low DC checks and High DC checks.
#2 Wow at the spin.

FrogReaver · Apr 19, 2018

With a character that:
1) focuses on stat growth
2) and focuses on skills in their highest stat area
3) and only faces DC's in range of DC 10 to DC 25 equally

Then:
At level 1: equivalent of +3.825 with advantage and +2 with expertise
At level 4: equivalent of +3.925 with advantage and +2 with expertise
At level 5: equivalent of +3.9875 with advantage and +3 with expertise
At level 8: equivalent of +4.0125 with advantage and +3 with expertise
At level 9: equivalent of +4.25 with advantage and +4 with expertise
At level 13: equivalent of +4.640625 with advantage and +5 with expertise
At level 17: equivalent of +4.90625 with advantage and +6 with expertise

Waiting till level 13 for expertise to finally start actually being better than advantage is something that really needs to be considered.