How to Calculate Debuffs

[Bopper]

How to Calculate Debuffs

When factoring in Strength, Resistance Debuffs, and Enemy Debuff Resistance

By Bopper

25 July 2020

 

Author’s Note

The motivation for this guide comes from a tool I developed from knowledge of the mechanics presented by Trickshooter and Frosticus. Their work helped me better understand how resistance debuffs interact with debuffs (Damage debuffs interact with Damage Resistance debuffs, To-Hit debuffs interact with To-Hit Resistance debuffs, and so on) and I wanted to pass along that information with examples and highlight how you can use the tool to do your own calculations. 

 

Some quick things with the format of this guide. First, I try to use wording that we see in the game, so I use the term "unresistable" whenever referring to an effect that ignores resistances. Also, there is a lot of verbiage on debuff resistances and resistance debuffs. That will come off as confusing, but I try to use consistent language when using the terms.

• A Resistance Debuff refers to when you debuff an enemy's resistance to debuffs. This effect is usually denoted in game as -Res(TypeDebuff) and it essentially acts as a way to increase the effects of that type of debuff applied on that target (similar to how debuffing damage resistance increases everyone's damage, debuffing a debuff resistance will increases everyone's debuff of that type).
• A Debuff Resistance refers to the amount of resistance an enemy has to debuffs. The equivalent to this is your character's debuff resistances such as defense debuff resistance (DDR) or recovery resistance.

Hopefully that clears it up, but if it is still too technical, just remember Resistance Debuff is good, Debuff Resistance is bad.

 

How Debuffs are impacted by Resistance Debuffs:

Trickshooter goes into excellent detail on the steps of these mechanics, but I’ll summarize the best I can. When a Debuff is applied, it has a base amount (e.g. Defender’s Radiation Infection does -31.25% To-Hit debuff and -31.25% Defense debuff). That debuff can be increased in strength from enhancements and/or strength buffing effects (like Power Boost). This serves as an effect multiplier, for instance let’s say you slot 20% enhancement to the To-Hit Debuff and you get 98.34% strength to To-Hit Debuff from Power Boost, the new To-Hit debuff would become -31.25% x (100% + 20% + 98.34%) = 68.23%.

 

However, Strength is not the only way you can improve your debuffs. You can also apply a resistance debuff to the target. This may show in the form of something like -40% Res(ToHit). This would apply a 40% resistance debuff to the target’s to-hit debuff resistance. Is that a mouthful? That’s because this is the same “resistance resists resistible resistance debuffs” situation you typically see discussed when talking about damage resistance debuffs (which I’ll get to shortly).

 

Let's now assume you face a Level 50 AV, which typically will have 85% resistance to all debuffs. So applying a 40% resistance debuff to their To-Hit will cause their new resistance to become:

New Debuff Resistance = 85% - 40% x (100% - 85%) = 79%.

 

Now that we have the final strength of our debuff and the final resistance of the target’s resistance to that debuff, we can calculate the final debuff applied to the target. Using the numbers in our example, we have 68.23% To-Hit debuff which the target resists 79% of, leaving the final debuff to be:

Final Debuff = 68.23% x (100% - 79%) = 14.33% To-Hit debuff.

 

There is a simple formula we can use to calculate these effects:

 

Final Debuff = (Base Debuff) x (1 + AddedStrength) x (1 + Res[Debuff]) x (1 – DebuffResistance)

 

In our example, that becomes:

 

Final Debuff = 31.25% x (1 + 0.20 + 0.9834) x (1 + 0.40) x (1 – 0.85) = 14.33%

 

There are other factors to consider, such as purple patch. This will impact the base debuff and it will impact the Resistance Debuff (Res[Debuff]) that is applied. So if you were facing a level 50 AV and you were only level 47, the +3 con of the enemy would make your effects have only 65% strength. This changes the results of the debuffs as so:

 

Final Debuff = (Base Debuff) x (Purple Patch Modifier) x (1 + AddedStrength) x (1 + (Purple Patch Modifier) x Res[Debuff]) x (1 – DebuffResistance).

 

In our example that would result in:

 

Final Debuff = 31.25% x 0.65 x (1 + 0.2 + 0.9834) x (1 + 0.65 x 0.4) x (1 – 0.85) = 8.38%

 

What about Damage Debuffs?

Damage Debuffs work in conjunction with the Damage Resistance of the target. Frosticus went into extensive detail on how this interaction works in their Poison Guide, but the big take away is Damage Resistance Debuffs will improve your Damage Debuffs, and because damage resistance varies by damage type, those damage debuff effects will also vary by damage type. This doesn’t change our formula from before, just need to factor in the damage type. The main difference is damage debuffs always ignore strength so you won’t have strength improvements from enhancements nor outside buffs:

 

Final Damage Type Debuff = (Base Damage Type Debuff) x (Purple Patch Mod) x (1 + (Purple Patch Mod) x ResistanceDebuff) x (1 -  DamageTypeResistance).

 

For an example, let’s use Defender’s Enervating Field which provides a 25% damage debuff and a 30% resistance debuff and we will assume the target is a Level 50 AV while we are Level 47. Let’s assume the AV has 40% resistance to Smashing Damage and 0% resistance to Energy Damage.

 

Final Smashing Damage Debuff = 25% x 0.65 x (1 + 0.65 x 0.30) x (1 – 0.40) = 11.65%

Final Energy Damage Debuff = 25% x 0.65 x (1 + 0.65 x 0.30) x (1 – 0) = 19.42%

 

This means we reduced the damage of Smashing attacks by 11.65% and we reduced the damage of Energy attacks by 19.42%. Ideally, you debuff an enemy that has low resistance to the type of damage they attack with. Next, let's compare these results to a 25% Damage Debuff with no Resistance Debuff and we can see the improvement made by the Resistance Debuffs:

 

Final Smashing Damage Debuff = 25% x 0.65 x (1 + 0) x (1 – 0.40) = 9.75%

Final Energy Damage Debuff = 25% x 0.65 x (1 + 0) x (1 – 0) = 15%

 

How to Apply this Formula for Calculating Damage

Damage can be treated as its own debuff, as it debuffs their health. Ok, I might be stretching with that comparison, but the nice thing is the formula doesn’t have to change:

 

Final Type Damage = (Base Type Damage) x (1 + AddedStrength) x (Purple Patch Mod) x (1 + (Purple Patch Mod) x ResistanceDebuff) x (1 – DamageTypeResistance)

 

Let’s assume we’re doing an attack that does 200 Smashing Damage and we have +95% enhanced damage and +30% global damage buff. We apply a 20% resistance debuff to an enemy that is +1 (0.90 purple patch) and they have 25% resistance to smashing damage.

 

Final Smashing Damage = 200 x (1 + 0.95 + 0.30) x 0.90 x (1 + 0.90 x 0.20) x (1 – 0.25) = 358.425 smashing damage.

 

How to incorporate Unresistable Debuffs and Unresistable Resistance Debuffs

So far, all discussion has only looked at resistible debuffs and resistible resistance debuffs. There are effects that can be unresistable which can include debuffs and resistance debuffs. This does not change the math at all, just expands the formula to breakout the resistible and unresistable portions.

 

Final Resistance Debuff = (Purple Patch Mod) x ( UnRes[Debuff] + Res[Debuff]x (1 - DebuffResistance) )

 

FinalDebuffResistance = DebuffResistance - (Final Resistance Debuff)

 

Resistible Debuff = (Base Resistible Debuff) x (1 + AddedStrength1)     // I am showing AddedStrength1 and AddedStrength2 to highlight the debuffs could be from different powers and thus have different enhancements.

 

Unresistable Debuff = (Base Unresistable Debuff) x (1 + AddedStrength2)   

 

Final Debuff = ( (Unresistable Debuff) + (Resistible Debuff) x ( 1 – (FinalDebuffResistance) ) ) x (Purple Patch Mod)

 

This certainly looks messier, but trying to fit it all into one formula might be a bit much to take in. So I hope breaking it out like this helps make sense of the steps used to calculate the Final Debuff amount. Luckily, unresistable debuffs and unresistable resistance debuffs are rare and hopefully you won't need to calculate them too often.

 

To help bring this home, let's assume a hypothetical power. Let's say we have a power that does 20% base to-hit debuff, however this power is unique in the fact half of that is unresistable. This would mean 10% can be resisted and the other 10% is not resisted. Let's assume the power is enhanced by 50%. The target we are debuffing has 85% resistance to to-hit debuffs and is +2 level con (80% strength purple patch). Finally, let's assume another power is used that provides a 40% resistance debuff to to-hit on the target (not enhanced, resistible). What is the final to-hit debuff on the target?

 

Final Resistance Debuff = 0.80 x (0 + 0.40 x (1 - 0.85) ) = 4.8%

FinalDebuffResistance = 85% - 4.8% = 80.2%

Resistible Debuff = 10% x (1 + 0.50) = 15%

Unresistable Debuff = 10% x (1 + 0.50) = 15%

 

Final Debuff = (15% + 15% x (1 - 0.802) x 0.80 = 14.376%

 

How to use the Resist/Debuff Calculator

To calculate all of the final Damage Debuffs use the first calculator in the Resist/Debuff Calculator sheet of Bopper's CoH Tools and Formulas. You can input the total amount of resistance debuffs, unresistable resistance debuffs (rare), damage debuffs, and unresistable damage debuffs. Next, select the Enemy Con level from the drop-down list and you input each of the different Damage Type Resistances the target has. Using our example of the +3 Level 50 AV and our Defender with Enervating Field we can see we get the same results by providing those parameters:

 

To calculate non-damage debuffs, you might find the bottom two calculators more useful. There is no functional difference between these two calculators, there are multiples simply for Quality of Life (QoL) purposes. You might want to look at two different debuffs side by side, so having two calculators can do that for you. Also for QoL purposes, you can compare up to 4 different targets in each calculator. You can change the purple patch effect and the debuff resistance for each of the 4 targets. Below, I plugged in numbers from a couple of the examples used in this guide:

 

In the top calculator I plugged in the numbers from the numbers of the Radiation Infection example. The 68.23125% To-Hit Debuff (after enhancement and power boost) is entered into the Debuff field. A hypothetical 40% Res(To-Hit) debuff was entered into the Resistance field. There were no Unresistable debuffs in this example. The final debuff was then calculated for 4 targets: Even Con enemy with no debuff resistance, an even con Level 50 AV with 85% to-hit debuff resistance, a +3 Level 50 AV with 85% to-hit debuff resistance, and a +4 Level 50 AV with 87% to-hit debuff resistance. The PP column represents the purple patch modifier, and its values are manually entered along with the resistances of the targets. The output breaks down the Final Resistance Debuff applied to each target, what the new Debuff Resistance becomes, and what the Final Debuff will be. We can see for the Even Con AV, the debuff was 14.33% and the +3 AV was 8.38%, just like in the examples above.

 

The bottom calculator performed the hypothetical unresistable debuff example. A 40% Res(To-Hit) was applied, as well at a 15% resistible To-Hit Debuff (after enhancement) and 15% unresistable To-Hit Debuff (after enhancement) were plugged into their respective fields. Compared to the +2 Level 50 AV with 85% to-hit debuff resistance, we see the final resistance debuff, new debuff resistance, and final debuff all match the results provided in the above example.

Edited July 26, 2020 by Bopper

[Bopper]

Revision History:

2020 July 25: Initial Document

[Bopper]

*Reserved*

Edited July 26, 2020 by Bopper

[Underfyre]

Out of curiosity, when you say damage debuff, do you mean their damage output of that type is debuffed, or the resistance to that damage type is debuffed and they will take more damage from it?

 

My experience with Damage Resistance is that they resist a portion based off of their damage resistance to that damage type.

 

If the mob has 30% resistance to Smashing damage and 0% to everything else, then is hit with 20% -res to all, it will take a 14% (20% * (1-30%)) hit to Smashing damage and 20% to everything else.

[Bopper]

On 7/29/2020 at 11:54 AM, underfyre said:

Out of curiosity, when you say damage debuff, do you mean their damage output of that type is debuffed, or the resistance to that damage type is debuffed and they will take more damage from it?

 

My experience with Damage Resistance is that they resist a portion based off of their damage resistance to that damage type.

 

If the mob has 30% resistance to Smashing damage and 0% to everything else, then is hit with 20% -res to all, it will take a 14% (20% * (1-30%)) hit to Smashing damage and 20% to everything else.

When I say damage debuff, it means their damage output of that type is debuffed.

 

HOWEVER, the enemy can resist your damage debuffs using their damage resistance. Let's use your example to illustrate what I mean. Let's say you apply a 40% damage debuff on the target, and the target has 30% resistance to smashing and 0% resistance to everything else. The final damage debuffs would be:

The enemy's smashing damage will be debuffed by 28% (40% * (1 - 30%))

All other damage from the enemy will be debuffed by 40% (40% * (1-0%))

 

Now let's say you apply a 20% resistance debuff on this enemy. Now the final damage debuffs would be:

The enemy's smashing damage will be debuffed by 33.6%

NewResDebuff = (20% * (100% - 30%)) = 14%

NewRes = (30% - 14%) = 16%

NewDMGDebuff = 40% * (100% - 16%) = 33.6%

 

All other damage from the enemy will be debuffed by 48%

NewResDebuff = 20%

NewRes = 0% - 20% = -20%

NewDMGDebuff = 40% * (100% + 20%) = 48%

 

Breaking it up line by line can be cumbersome, so I use the formulas from my original post:

NewDebuff = Debuff x (100% + ResDebuff) x (100% - EnemyResist)

NewDebuff = 40% x (100+20%) x (100%-30%) = 40*1.2*0.7 = 33.6%

Edited August 3, 2020 by Bopper

[CaptainLupis]

I have a question about resistance debuffs, wasn't sure where to ask it but this seems like a good place to start.

 

If you are over the hardcap for res and get hit with a debuff, does the debuff value get taken from the hardcap value or from the actual res value?

 

For example, if I have smash/lethal res of 100%, which is reduced to 90% on a tank due to the cap, and they get hit with a 10% res debuff would that come off the 100 or 90? I'm presuming it just ignores the extra but I'm not sure. I just want to make sure it's not worth going for more to help deal with res debuffs.

[Bill Z Bubba]

1 hour ago, CaptainLupis said:

I have a question about resistance debuffs, wasn't sure where to ask it but this seems like a good place to start.

 

If you are over the hardcap for res and get hit with a debuff, does the debuff value get taken from the hardcap value or from the actual res value?

 

For example, if I have smash/lethal res of 100%, which is reduced to 90% on a tank due to the cap, and they get hit with a 10% res debuff would that come off the 100 or 90? I'm presuming it just ignores the extra but I'm not sure. I just want to make sure it's not worth going for more to help deal with res debuffs.

Should work just like defense and come off the top, not the cap. And since resistance resists resistance debuffs, if you're that far over the cap, you'll probably never see your resistance for that type debuffed by said resistance debuffs.

[CaptainLupis]

1 minute ago, Bill Z Bubba said:

Should work just like defense and come off the top, not the cap. And since resistance resists resistance debuffs, if you're that far over the cap, you'll probably never see your resistance for that type debuffed by said resistance debuffs.

I just wonder if it's different as it's a hard cap, not a soft cap like defence is.

[Bill Z Bubba]

3 minutes ago, CaptainLupis said:

I just wonder if it's different as it's a hard cap, not a soft cap like defence is.

I hear ya. Trying and failing to come up with a way outside of PvP to test that... Anybody have any ideas?

[Bopper]

Good questions. I often wondered this myself but have never tested it. 

1 hour ago, Bill Z Bubba said:

I hear ya. Trying and failing to come up with a way outside of PvP to test that... Anybody have any ideas?

Go into a mission where you know an enemy has a certain amount of debuff and take Teleport Foe with you. Preferable, do not have capped resistance to everything. Monitor your combat attributes and see how much of a debuff is applied across all damage resistance types. 

 

I recommend take a character with silly dumb levels of resostance (like electric armor having 130% resistance to energy) and see if you get debuffed if you dip below 90% or remain at 90%. To know how much the true debuff is, you can look at your sub capped resistance to see their debuff amounts and back it out to an original amount. That might help to analyze your capped resistance test.

[Bopper]

@CaptainLupis and @Bill Z Bubba

 

Thank you for pointing me into looking at this. I learned something new. Bill, you were right, the extra damage resistance makes for a buffer plus the resistance to debuffs grows stronger. Take a look at this screen shot and pay attention to Lethal Resistance.

 

 

Prior to the debuff, I had 93.22% resistance to Smashing/Lethal damage (which caps at 90%). Then I got hit with a 53.20% resistance debuff. However, my end result was 89.61% resistance. I only dropped from 90% to 89.61% despite a 53.20% resistance debuff? BUT HOW?!?!?!

 

My resistance to the debuff was in fact 93.22%. So of that 53.20%, I only took:

-53.20% x (100% - 93.22%) = -3.61% resistance debuff.

 

Then, that resistance debuff took away from my full resistance, not my capped resistance. Thus my new Damage Resistance became:

NewResistance = 93.22% - 3.61% = 89.61%.

 

I did another test to see if there could be cascading failure, but it appears not the case. Here I took 2 debuff:

 

My new starting resistance was 93.72% (reactive defense scaled up to 3.5%). Now I had 106.4% resistance debuffs applied to me yet my resistance only fell to 87.03%. Here is what I was expecting:

New Debuff = -106.40% x (100% - 93.72%) = -6.682%

New Resistance = 93.72% - 6.68% = 87.04%

 

So no, there is no cascading resistance failure. You simply take all of your resistance buffs and add them up, then you take all your resistance debuffs and add them up, then you do the math like we know how to do.

 

This makes for an interesting case with Resistance armor sets. If you have 100% resistance, you will never get debuffs (unless it's "unresistable" debuffs). But even then, just having a buffer, let's say 95% resistance, makes it such that it would require: 5% / (1 - 0.95) = 100% resistance debuffs just to get you to fall under 90%.  With 97.5% resistance, it would take: 7.5% / (1 - 0.975) = 300% resistance debuffs. This also gives non-Tank ATs a reason for surpassing their own 75% resistance caps, as the buffer will not only resist more resistance debuffs, it will give you a better chance to prevent your resistance from actually dropping below 75%.

 

Edit: Additional info,

I was curious if your resistance to resistance debuffs would be capped at 95% (similar to DDR). It appears not to be the case. I tested with 95.83% resistance, got hit with 230.4% resistance debuffs, and my final resistance was 86.25% (my math said 86.22%, but it could be rounding error). If it capped at 95% my resistance would have been 84.31%, so it's clear I was getting the full 95.83%. Pretty nice.

Edited August 7, 2020 by Bopper
extra testing to see if there was a 95% cap for resisting debuffs. There isn't.

[CaptainLupis]

1 hour ago, Bopper said:

@CaptainLupis and @Bill Z Bubba

 

Thank you for pointing me into looking at this. I learned something new. Bill, you were right, the extra damage resistance makes for a buffer plus the resistance to debuffs grows stronger. Take a look at this screen shot and pay attention to Lethal Resistance.

 

 

Prior to the debuff, I had 93.22% resistance to Smashing/Lethal damage (which caps at 90%). Then I got hit with a 53.20% resistance debuff. However, my end result was 89.61% resistance. I only dropped from 90% to 89.61% despite a 53.20% resistance debuff? BUT HOW?!?!?!

 

My resistance to the debuff was in fact 93.22%. So of that 53.20%, I only took:

-53.20% x (100% - 93.22%) = -3.61% resistance debuff.

 

Then, that resistance debuff took away from my full resistance, not my capped resistance. Thus my new Damage Resistance became:

NewResistance = 93.22% - 3.61% = 89.61%.

 

I did another test to see if there could be cascading failure, but it appears not the case. Here I took 2 debuff:

 

My new starting resistance was 93.72% (reactive defense scaled up to 3.5%). Now I had 106.4% resistance debuffs applied to me yet my resistance only fell to 87.03%. Here is what I was expecting:

New Debuff = -106.40% x (100% - 93.72%) = -6.682%

New Resistance = 93.72% - 6.68% = 87.04%

 

So no, there is no cascading resistance failure. You simply take all of your resistance buffs and add them up, then you take all your resistance debuffs and add them up, then you do the math like we know how to do.

 

This makes for an interesting case with Resistance armor sets. If you have 100% resistance, you will never get debuffs (unless it's "unresistable" debuffs). But even then, just having a buffer, let's say 95% resistance, makes it such that it would require: 5% / (1 - 0.95) = 100% resistance debuffs just to get you to fall under 90%.  With 97.5% resistance, it would take: 7.5% / (1 - 0.975) = 300% resistance debuffs. This also gives non-Tank ATs a reason for surpassing their own 75% resistance caps, as the buffer will not only resist more resistance debuffs, it will give you a better chance to prevent your resistance from actually dropping below 75%.

 

Edit: Additional info,

I was curious if your resistance to resistance debuffs would be capped at 95% (similar to DDR). It appears not to be the case. I tested with 95.83% resistance, got hit with 230.4% resistance debuffs, and my final resistance was 86.25% (my math said 86.22%, but it could be rounding error). If it capped at 95% my resistance would have been 84.31%, so it's clear I was getting the full 95.83%. Pretty nice.

Thanks for looking into that and testing it, much appreciated. I actually assumed it would be something already fairly well known about and I was just out the loop on it as I usually go more defence than res based.

 

It certainly makes things like Meltdown (and other T9 res powers) and rune of protection more interesting, even for those at or near the cap, as buffers against res debuffs.

 

Cheers.

[Bopper]

Today, had a good discussion with @Elmyder on the interaction of unresistable resistance debuffs and how they affect additional resistible resistance debuffs. It turns out the math I showed was wrong, so I will be correcting that shortly to reflect the correct order of operations.

 

On a separate note that is related, @Veracor provided some excellent testing today which I want to share their results. This screenshot is of a character with 102% S/L resistance (uncapped, obviously) taking on 997.5% resistance debuffs. They came out of it still with 90% damage resistance. For all practical purposes, it's safe to say having 100% damage resistance will prevent you from suffering from any resistible resistance debuffs. Another note Veracor mentioned (I didn't want to do the math to verify, so I'll take his word...Update, I put the numbers into my calculator, it checks out), he used an orange inspiration (Robust, +20%), which took their damage resistance from -97% up to 90%. Amazing the difference in being able to resist 82% of a debuff versus 100% 🙂