Optimizing Sneak Attack damage with multiple attacks

[banthafett]

If a character with the Sneak Attack ability, and multiple attacks, hits with an attack, should they apply their Sneak Attack damage to that attack, or should they wait until they've made more attacks to see if they get a critical?

That's the question I'm attempting to answer with this spreadsheet. What it does is calculate the probability that you will hit with subsequent attacks and adds the chance that you will crit to determine if your expected Sneak Attack damage will be higher if you wait than if you use it immediately. It is meant to be edited to reflect the specific situation you are facing. Please save a copy in order to make changes. It applies equally well to any situation where you have a source of damage that you will only be applying once in a given number of attacks such as a Smite.

Should I Sneak Attack? (https://docs.google.com/spreadsheets/d/1dPc2sZ8iD7hnKtp9g7LaxqH1KSLaOzIqh7QTKFx149E/edit#gid=0)

Edit: There was an error in the math of the original version of the spreadsheet. An attack equal to the target AC was treated as a miss. If you previously downloaded the spreadsheet, please re-download to correct the issue.

[Specter]

Since the possibility of critting will always be smaller than the chance of missing, it doesn't sound like a good idea.

Ok, 'always' may ne a little much because gelatinous cubes exist, but it will be at least the same.

[banthafett]

Since the possibility of critting will always be smaller than the chance of missing, it doesn't sound like a good idea.


The math doesn't actually bear that out though, especially the more attacks you have. For example, if you have +5 attack, advantage, the Elven Accuracy feat, and one attack remaining, and your opponent has 15 AC you will, statistically, do ~2% more Sneak Attack damage over time by holding on to your Sneak Attack damage for your next attack. If you were a Fighter multiclass and had Extra Attack so you had two attacks remaining you would do ~25% more Sneak Attack Damage by waiting. If, additionally, you were using Action Surge this turn and therefore had four attacks remaining, you would do ~46% more Sneak Attack damage by waiting.

The purpose of this tool is to remove ambiguity. You can just plug in the numbers and see the result, and not have to rely on intuition, which often steers us wrong when it comes to probabilities.

[Helliquin]

If a character with the Sneak Attack ability and multiple attacks hits with an attack, should they apply their Sneak Attack damage to that attack, or should they wait until they've made more attacks to see if they get a critical?

That's the question I'm attempting to answer with this spreadsheet. What it does is calculate the probability that you will hit with subsequent attacks and adds the chance that you will crit to determine if your expected Sneak Attack damage will be higher if you wait than if you use it immediately. It is meant to be edited to reflect the specific situation you are facing. Please save a copy in order to make changes. It applies equally well to any situation where you have a source of damage that you will only be applying once in a given number of attacks such as a Smite.

Should I Sneak Attack? (https://docs.google.com/spreadsheets/d/1dPc2sZ8iD7hnKtp9g7LaxqH1KSLaOzIqh7QTKFx149E/edit#gid=0)

I've started playing a character and have theorycrafted its progression.

Ranger 3 (Gloom Stalker), Monk 5 (drunken master), Rogue 3 (Assassin), Fighter 3 (Brute), Rogue (4-5).
So at level 16, provided I have surprise, action surge and enough ki, thats 6 attacks on initial round of combat. But I will have auto crits and advantage on first round of combat - thus optimizing without the need to do the math. :)

Max damage is:
Attack 1(2d6+2+2d6+5+2D4)
Attack 2(2d6+2+2d6+5+2D4)
Action Surge (2d6+2+2d6+5+2D4)
Gloom Stalker extra attack (2D6+2+2D6+2D8+5+2D4)
Flurry of blows (2d6+5+2d6+2D4)+(2d6+5+2d6+2D4)
Sneak Attack 6D6

Your spreadsheet tells me I should never Sneak attack :(

At least until I read the disclaimer at the bottom which tells me that im free to use it on my first attack...

[Citan]

If a character with the Sneak Attack ability and multiple attacks hits with an attack, should they apply their Sneak Attack damage to that attack, or should they wait until they've made more attacks to see if they get a critical?

That's the question I'm attempting to answer with this spreadsheet. What it does is calculate the probability that you will hit with subsequent attacks and adds the chance that you will crit to determine if your expected Sneak Attack damage will be higher if you wait than if you use it immediately. It is meant to be edited to reflect the specific situation you are facing. Please save a copy in order to make changes. It applies equally well to any situation where you have a source of damage that you will only be applying once in a given number of attacks such as a Smite.

Should I Sneak Attack? (https://docs.google.com/spreadsheets/d/1dPc2sZ8iD7hnKtp9g7LaxqH1KSLaOzIqh7QTKFx149E/edit#gid=0)
Thank you very much for sharing! I'll get a look at it when I have some time and brain availability. XD

Since the possibility of critting will always be smaller than the chance of missing, it doesn't sound like a good idea.

Ok, 'always' may ne a little much because gelatinous cubes exist, but it will be at least the same.
Err... No?
Properly optimized "basic" Fighter (disregarding archetype features or feats) will get starting +5 (+2 prof, +3 stat) and end with +11 (+6 prof, +5 stat).

Chance to crit AC 12 is the same as chance of missing because 1 is auto-fail.

Now, there are many ways to bump the starting threshold at which you need to roll for anything else than "not 1". Bless, Elemental Weapon, Precision Attack, Bardic Inspiration, etc...
The same optimized martial in a decent party could expect auto-hit (again, barring auto-fail 1) up to AC 13-14.

Now, build a character specifically to maximize reliability (Hexblade Warlock 1 / Devotion Paladin 3 / Champion Fighter X), you have 95% chance to hit up to AC 16, before any other boost from you (Bless Action Surge) or other.
Then comes advantage, and the broken triple advantage from Elven Accuracy.
Getting advantage is not usually that hard either except when you fight some casters or high-level creatures that can resist your advantage effects or impose a source of disadvantage to compensate.
Now you'd need to roll three 1 in a row to fail your attack. Probability of that happening is abysmal.

Even against a 20 AC, you still need to roll just a 4. On three rolls, the ability of getting at least one equal or above to that is still near 99%. :)

With that said, I agree that on actual play, from level 1 to 11 at least, I would rarely "wait" for a crit unless I'm really targeting bad AC with triple advantage. ^^

[banthafett]

I will have auto crits and advantage on first round of combat...

...Your spreadsheet tells me I should never Sneak attack :(

At least until I read the disclaimer at the bottom which tells me that im free to use it on my first attack...

Yep, the situation being addressed by the spreadsheet is having hit with an attack, but not crit, and having at least one attack remaining. If your current attack is a crit, or you have no attacks remaining, you can always apply Sneak Attack damage to your current hit for maximum Sneak Attack damage.

[banthafett]

There was an error in the math of the spreadsheet prior to this post. An attack roll equal to target AC was being treated as a miss. If you downloaded a copy of the spreadsheet please re-download to fix the error.

[Specter]

Looking the math over, I can say I was wrong. But still it's not something I would attempt unless I had Elven Accuracy or a Champion multiclass.