Introduction

Hello r/PathOfExile2, I am sure all of you saw the new Amazon ascendancy for the Huntress and a particular node within piqued my interest. The so called Critical Strike (Terrible name by the way, I hope it is just a placeholder). Here is the node for those unable to recall:

Critical Strike
Chance to hit with Attacks can exceed 100%
Gain additional Critical Hit Chance equal to 25% of excess chance to hit with Attacks

The Accuracy Formula

According to Path of Exile 2 Wiki the accuracy formula is^([1]):

Uncapped Chance to Hit = (Attacker's Accuracy * 1.5) / (Attacker's Accuracy + Defender's Evasion) * (1 - Accuracy Penalty) * 100
Capped Chance To Hit = max(min(Uncapped Chance to Hit, 100), 5)

Where accuracy penalty starts applying after 2 meters and reaches its maximum 0.9 at 12 meters. The correctness of this formula is backed by Path of Building 2^([2]):

function calcs.hitChance(evasion, accuracy)
	if accuracy < 0 then
		return 5
	end
	local rawChance = ( accuracy * 1.5 ) / ( accuracy + evasion ) * 100
	return m_max(m_min(round(rawChance), 100), 5)
end

Path of Building 2 does not yet support hit chance calculations based on distance. Moving forward all of the assumptions will be made according to this formula with no accuracy penalty.

The Critical Strike node removes the second part and allows you to exceed 100% hit chance. If we assume enemy's evasion as constant then the formula can be simplified into:

Uncapped Chance to Hit = (Attacker's Accuracy * 1.5) / (Attacker's Accuracy + ε)

which approaches 150% as the accuracy approaches infinity. This gives us a theoretical upper limit of 50% extra chance to hit which is then converted into 12.5% additional critical hit chance. But to calculate it's practical benefits we need to take enemy's evasion into account. According to Path of Building 2 a level 85 enemy (An Uber Pinnacle Boss) has a base evasion of 724^([3]):

local data = ...
-- From DefaultMonsterStats.dat
data.monsterEvasionTable = { 11, 14, 17, 20, 24, 27, 31, 35, 38, 42, 46, 50, 54, 59, 63, 67, 72, 76, 81, 86, 91, 96, 101, 106, 111, 117, 122, 128, 134, 140, 146, 152, 158, 165, 171, 178, 185, 191, 199, 206, 213, 221, 228, 236, 244, 252, 261, 269, 278, 286, 295, 304, 314, 323, 333, 343, 353, 363, 373, 384, 395, 406, 417, 429, 440, 452, 464, 477, 489, 502, 515, 528, 542, 556, 570, 584, 598, 613, 628, 644, 659, 675, 691, 708, 724, 742, 759, 777, 795, 813, 832, 850, 870, 889, 909, 930, 951, 972, 993, 1015, }

This value is further backed by PoE2DB*^([5])* yet according to Path of Building 2 developers this table is off by 0.5% in some cases*^([4])* but the difference is insignificant enough that I won't do the correction.

This 724 base evasion is then further scaled by the specific evasion multipliers of uber bosses. Unfortunately for now these values are unknown however in Path of Exile 1 these ranged from 1 (for Maven, Sirus, etc.) to 1.5 (for Searing Exarch) and I will assume Path of Exile 2 bosses have similar ranges. Assuming a 1.5 multiplier our final evasion becomes 1086. Here is a table that shows the additional critical hit chance granted at specific intervals:

Accuracy Rating	Hit Chance	Additional Critical Hit Chance
500	47.29%	0%
1000	71.91%	0%
2000	97.21%	0%
2172	100.0%	0%
4000	117.97%	4.49%
8000	132.07%	8.02%
16000	140.47%	10.12%
32000	145.07%	11.27%

Discussion

As you can see after ≈12.000 accuracy rating the additional critical hit chance granted by the Critical Strike node has diminishing returns. A build which heavily invests into Accuracy can reach ≈16.000 accuracy without much problem thanks to dexterity stacking (+5 accuracy rating per dexterity). This number can go as high as ≈32.000 if min-maxing every point of dexterity and accuracy rating.

Now that we have established how much additional critical hit chance from the Critical Strike node we should talk about what 'Additional Critical Hit Chance' even is. I see 4 options as to what it means, these are from the mostly powerful to the least:

1. Added Critical Hit Chance

Additional critical hit chance acts additively with other base critical hit chance modifiers. This behaviour is supported by Path of Exile 1 Wiki's Critical Strike^([6]) and Brittle^([7]) entries. Technical jargon could change between games but I personally don't see any reason for this to be the case.

2. 'On Top' Critical Hit Chance

Additional critical hit chance acts 'on top' of your critical hit chance after all other modifiers have been applied. So if you have 10% additional critical hit chance then you only needs to reach 90% critical hit chance to guarantee a critical hit. I don't believe there is an item/modifier that acts like this but it is possible it's new.

3. More Critical Hit Chance

Additional critical hit chance acts as a more multiplier to your critical hit chance after all other modifiers have been applied. So if you have 10% additional critical hit chance and 90% critical hit chance then you have a 99% final critical hit chance.

4. Increased Critical Hit Chance

Additional critical hit chance acts as a increase to your base critical hit chance. This being the case seem impossible to me as a ascendancy point granting only 12.5% increased critical hit chance when investing into it heavily is simply weak. Especially considering small nodes in the passive skill tree grant 10-15% critical hit chance.

Conclusion

I believe this node can be a very powerful tool if it acts as a base critical hit chance modifier. Especially considering stacking 16000 accuracy rating and 900 dexterity gives you 124% increased attacks speed through Falcon Dive and Falcon Technique notables.

References

[1] https://www.poe2wiki.net/wiki/Accuracy
[2] https://github.com/PathOfBuildingCommunity/PathOfBuilding-PoE2/blob/dev/src/Modules/CalcDefence.lua#L31
[3] https://github.com/PathOfBuildingCommunity/PathOfBuilding-PoE2/blob/dev/src/Data/Misc.lua#L5
[4] https://github.com/PathOfBuildingCommunity/PathOfBuilding-PoE2/blob/dev/src/Export/Scripts/miscdata.lua#L28
[5] https://poe2db.tw/us/Xesht%2C_We_That_Are_One#XeshtWeThatAreOneItThatReturned
[6] https://www.poewiki.net/wiki/Critical_strike#Mechanics
[7] https://www.poewiki.net/wiki/Brittle