INTRODUCTION:

Critical stats is a crucial part in boosting damage in Dragon Nest, especially for damage dealing classes. The mechanics of critical damage will be explained in this guide, with some calculation examples.

MECHANICS

What is Critical Damage?

Critical damage is the damage dealt without taking into account the effect of phy/mag defence of your target. A extra multiplier of 1.25 is imposed on that damage too, which is shown in the following equation:

Normal Non-crit damage = (%Amp * M.att + Add. dmg)*(1 - %dmg reduction from defence)

Crit Damage = 1.25 * (%Amp * M.att + Add. Dmg)

1.25 : 1.25 is the crit damage multiplier applied if crit happen.
%Amp: % of skill amplification in the skill description.
M.att: Your magic attack in stats window.
Add. Damage: Additional damage in the skill description.

In battle, the color of the crit damage figure = yellow/gold.

For the sake of the discussion, i call that “Yellow Critical”.

Critical stats in your stats window is a figure that tells you, the probability to deal critical damage.

The equation that convert the stats to the % probability has been derived and proven to be approximately linear.

Now here comes the other important point question.

What is Critical Resist?



A natural idea that comes to mind, is that Critical resist would reduce the chances of your opponent to deal critical damage to yourself. However, that’s absolutely NOT true.

It has been proven also that Critical Resist is actually related to the chance of reducing the critical damage figure dealt to you.

When critical damage is resisted, in addition to the 1.25 multiplier, another multiplier of 0.35 is applied over the damage.

Resisted Crit Damage = 1.25 * 0.35 * (%Amp * M.att + Add. Dmg)

So, resisted critical damage will be much lower than normal non-crit/crit damage.
Critical damage that has been resisted, will appear whitish with a crack across the word "critical". Hence we normally call it “White Critical”. If you’ve fought electric ogre in apocalypse or lava golem in Sea Dragon Nest, you will see this White Critical very often.

I hope that clears up the concept of Crit and Crit resist.

Interestingly, the investigation doesn’t stop there.

Does higher crit reduce the chances of dealing White Crit?

It has also been proven that 10,000 crit and 20,000+ crit has almost the same probability on dealing white crit on the same target with a constant crit resist.

The only effective way to reduce white crit is by using wind prefix weapon.

Crit resist is actually double edge sword type of stats . It will make your opponent deal alot of white crit if he has very high crit stats, while it is useless against an opponent that has very low crit.

Can White Crit damage be higher than normal non-crit damage?

In order for the damage of high crit to surpass the normal non-crit damage, the boss defence need to exceed a certain threshold:

1.25 * 0.35 > ( 1 - def)

def > 56.25%

as you can note from bishop nest (see table below), none of the boss in bishop has over 56.25% of defence.

It is actually a pretty high value,which translate to 8438 of defence stats.

So in general, you can say that white crit is lower than non-crit damage, with maybe afew exception for bosses with extremely high defence (> 56.25% , such as Green Dragon, Kalahan, Morgan, White Eye Cyclops in Green Dragon Nest)

Ok, if you have understood everything that i described, you must be wondering why would the developer allow players to get seemingly infinite crit stats if there is a cap of 95% crit chance.

The answer is :

The crit chance is dependant on the level of your target.

Against lv32 monster, 6000 crit stats will net you 95% crit chance.
Against lvl40 monster, 10,000~11,000 crit stats will give you 95% crit chance.
Against lv50 monster, 17,000~18,000 crit stats will give you 95% crit chance.

This explain why some people are seeing less crit damage against high level monsters, especially in lv50 abyss and Darklair (with lv100 monster/boss).

Since the critical stats is proven to be linear, you can scale it according to your current crit stats to find out the % chance to deal critical damage.

Do note that the number above are approximate figures only. Since crit damage is based on probability, the real chance can only be obtained with a lot of test.

CASE STUDY:

Is crit good? What is better? M.att or Elemental Attack or Crit?

These are the most common questions asked in various Dragon Nest forum.

Although the answer is not exactly straight forward, but there are exact answers to these question.

To answer them, you will need to know what is your defence of your target.

Crit and Phy/Mag Defence:

I will use bishop nest bosses as examples:



Full stats of the BOSS can be found here:

http://dn.duowan.com/1112/188138585875.html

The bracket behind the boss name shows the stage they appear at.

How do i determine their defence?

1. Take a weapon with no durability (so that your damage won't fluctuate)
2. Use normal attack on the boss.
3. Note down the crit damage and non crit damage.
4. Calculate the m.def by :

M. Def % = 1-  1.25 * Non-crit damage / crit damage

The crit damage is obviously the same, no matter what boss you hit, in my case it is 950 since crit damage ignore the defence of the target.

FYI, The mag / ph def value can be translated to % damage reduction, which are dependant on the ATTACK'S LEVEL (not dependant on the TARGET'S LEVEL).

For a Lv41 Attacker: every 3000 def = 33.33% damage reduction.
For a Lv45 Attacker: every 3000 def = 26% damage reduction.
For a Lv50 Attacker: every 3000 def = 20% damage reduction.

[ see Ref 3]

Note that high crit/non crit ratio for the high defence bosses.

This shows that if you crit against high defence boss such as shadow and bishop base, you will get 2.47 times of damage !! On the other hand, if you crit against low defence boss such as assasin, you will only get 1.54 times of damage.

In general, Critical is more effective when the target has high defence and low critical resist.

Choices of Ring

Now lets say my current majesty stats are:

5500 m.attack, 30% dark elemental attack, 8000 crit

And, i am given a choice between:
A) Lv50 A-ranked Magical Ring (153 m.att, 55int)
B) Lv50 A-ranked Knight Ring (102 m.att, 589crit)
C) Lv50 A-ranked Critical Ring (1325 crit, 61 agi)
D) Lv50 A-ranked Brilliant Ring (76 m.att, 5.8% dark)
E) Lv50 A-ranked Skill Ring (1121 crit, 3.54% dark)

Lets say all of the above doesn't come with potential and i are not wearing any crest or other items with potential (all those will make this example far more complicated, though you can include them once you know the concept)

Assuming no crit resist and no elemental resist on hit, and i am using Lv12 Gravity ball only to deal damage.

Gravity ball lv12: 2.69% + 3760

Which ring should i use?

Since the bosses in bishop nest have very different m.def value, we will take a average for all of them,  which is  34.6%.

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A) Remember that 1 int = 0.75 for mages, so the total damage attack gained is 153 + 0.75*55 = 194

Crit damage = 1.25 * (2.69 * 5694 +3760) * 1.3 = 31000

[ The 1.3 multiper is due to 30% dark elemental attack currently on me ]

Non crit damage = (2.69 * 5694 +3760) * 1.3 * (1-0.346) = 16219

[ The 0.346 is the average damage reduction from defence value of the bishop bosses ]

With 8000 crit, the chance to deal crit damage is

8000/17000*95% = 44.7%.

[ scaling the crit for lvl50 target linearly. ]

Therefore, Average damage = 31000 * 0.447 + 16219 * (1 - 0.447) = 22826

[ average damage = crit damage * crit chance + non crit damage * ( 1- crit chance) ]

=========================

B) Gain 102 m.att and 589 crit.

Crit damage = 1.25 * (2.69 * 5602 +3760 ) *1.3 = 30598

Non crit damage = (2.69 * 5602 +3760) * 1.3 * (1-0.346)  = 16009

With 8000+ 589 =8589 crit, the chance to deal crit damage is

8589 / 17000 * 95% = 48.0%

Therefore, Average damage = 30598 * 0.48 + 16009 * (1-0.48) = 23011

=========================

C) 1 agi = 3.5 critical. So the total gain in crit is 1325+61*3.5 = 1538

Crit damage = 1.25 * (2.69 * 5500 +3760 ) *1.3 = 30152

Non crit damage = (2.69 * 5500 +3760) * 1.3 * (1-0.346)  = 15775

With 8000+ 1538  = 9538 crit, the chance to deal crit damage is

9538 / 17000 * 95% = 53.3%

Therefore, Average damage = 30152 * 0.533 + 15775 * (1-0.533) = 23437

=========================

D) I gain 76 m.att and 5.8% dark by using briliant ring. straight forward.

Crit damage = 1.25 * (2.69 * 5576 +3760 ) *1.358 = 31844

Non crit damage = (2.69 * 5576 +3760) * 1.358 * (1-0.346)  = 16660

With 8000 crit, the chance to deal crit damage is

8000 / 17000 * 95% = 44.7%

Therefore, Average damage = 31844 * 0.447+ 16660* (1-0.447) = 23447

=========================

E) I gain 1121 crit, 3.54% dark

Crit damage = 1.25 * (2.69 * 5500 +3760 ) *1.3354 = 30973

Non crit damage = (2.69 * 5500 +3760) * 1.3354 * (1-0.346)  = 16205

With 8000 +1121 crit, the chance to deal crit damage is

9121 / 17000 * 95% = 51.0%

Therefore, Average damage = 30973 * 0.51+ 16205* (1-0.51) = 23736

=========================

CONCLUSION

Here, if i were to maximize the damage of my gravity ball, i would choose E. Skill Ring.

Having said that, Skill Ring has 10 different stats, which are given at random when crafted and the success chance is only 30%.

It is interesting to note that cheap thing such as Knight Ring is actually better than the expensive magical ring.

However, do note that this conclusion SHOULT NOT BE GENERALIZED.

The answer to the question should depends on your current stats, potential, target monster and your skill.

You have to go through the steps above on your own when making choices.

I will probably have to make another article on how to calculate stats based on your potential, heraldry and stuff soon. After learning all these, you can easily evaluate the gain from each gear and decide which is the best gear for you.

APPENDIX  A:
For a case study on crit calculation for lv32 cap, see
http://forum.mmosite.com/thread/2/217/20101111/Chaos_PVE_Majesty_Guide-4dac375f362242413-19.html#p4eaf7471044cd5

Notice that the priority for dmg boosting can be very different at various level cap.


Reference:
1. http://forum.mmosite.com/thread/2/217/20110317/Mercenary_Tier_3_Job_Barbarian_Destroyer-4dac37601af662213-9.html#p4db04f7127f185
2. http://bbs.duowan.com/thread-21292172-1-2.html
3. http://bbs.duowan.com/thread-22283212-1-2.html