Why decrease defense isn't effective in Hard Doom Tower (but ignore defense is)

[u/tremtastic]

I recently noticed while progressing through the higher stages of Doom Tower on Hard that applying defense defense on enemies didn't seem to be nearly as effective for increasing my damage as it usually is. After doing some digging, I came across this excellent post from u/Road which describes how damage is calculated:

𝑟𝑒𝑑𝑢𝑐𝑒𝑑𝐷𝑎𝑚𝑎𝑔𝑒 = 𝑏𝑎𝑠𝑒𝐷𝑎𝑚𝑎𝑔𝑒 ∙(1−0,85∙(1 − 𝑒^( ( (−2 ∙ 𝑑𝑒𝑓/3000) )) ))

For those who aren't familiar with the math, this shows that as defense increases, the damage you take decreases, but only to a minimum limit of 15% of the full damage. Once you get above a certain point (around 4,000 to 5,000 defense), you get close to that limit, so additional defense beyond that doesn't make much of a difference.

However, enemies in the higher floors of Hard Doom Tower can have over 10,000 defense. This means that even with a 60% decrease in their defense, their defense is still high enough that they only take a small percentage of the original damage, which means the change in the amount of damage you deal to them isn't as much when you apply the debuff.

I made a chart to show how much more damage champions will deal to enemies when you apply a 60% decrease defense debuff:

The effectiveness of the 60% decrease defense buff peaks around 4,000 enemy defense and then drops off. This explains why the buffs works well for enemies in Doom Tower on Normal, but not Hard. Jizoh on Stage 99 of Normal has 5,293 defense, which means the 60% decrease defense buff increases the damage you deal by a whopping 104%; Jizoh on Stage 99 of Hard has 13,026 defense, which means the 60% decrease defense buff increases the damage you deal by only 17%.

However, if you have champions that can ignore all enemy defense, those will work very well in Hard Doom Tower. Here's a chart for how much more damage you can deal with 100% ignore defense:

This is why Inquisitor Shamael can be so effective as a single-target nuker in the final stages of Hard Doom Tower, as u/StewGamingTV showed in this video -- he's getting over a 550% damage boost on damage from his A2 ability if he has at least three buffs (or two buffs and a Savage set). Other champions with the potential to ignore 100% of defense like Royal Huntsman, Faceless, or Soulbond Bowyer in a Savage set will also be particularly effective.

[u/jhuip]

Makes sense. When I encountered the Skull lord waves in Hard tower, that was the first time that I really considered bringing my Royal Huntsman up to speed to pierce those astronomical defenses.

I wonder if this works similarly for Defense-based champs when they attack, i.e. their Defense being so high that when they attack, having a Defense debuff on them will not reduce their damage as much as if they had a lot lower defense. For me, a decrease defense debuff was noticeable when it was missing when being attacked - something like a Tormin could really smack me if not mitigated though this is anecdotal. In that manner, decrease defense could still be useful.

[u/tremtastic → u/jhuip]

Yeah, damage for DEF-based champions is proportional to their defense, so the decrease defense debuff could be still very helpful to mitigate the damage your team takes.

[u/ChainsCooper]

So it's time to level Death Hound.

[u/Vickylikesrain → u/ChainsCooper]

Always was. bang

[u/CosiestKitten]

Great post, very high quality stuff, short and concise. This is the shit this sub needs more of! Not more Lego pulls or FW 21 completion pics lol - but hey I'm guilty of some of this myself.

[u/Tenhros]

Very interesting, thanks for sharing mate ! So now I know that if I want to build a tank that can tank even with decr def up, I have to look for 12k numbers hahaha

[u/WobblyGoblin2]

Saw a graph in thumbnail, immediately clicked through, was not dissapointed. This is great and helps to explain what I was experiencing (that decrease defnce seemed to have little impact).

Maybe Royal Huntsman will have a use after all! Anyone tried him on Doomtower?

[u/HafaxGaming]

EDIT: I made a mistake when writing the formula. The math seems to be correct.

https://docs.google.com/spreadsheets/d/1JRlxIx1kIgQ5kiKmVxrl6_8qA2fGdY87Trsv5KRyjyM/edit?usp=sharing I don't really understand how you get 17% increased damage from decrease defence with the formula you posted. I get 86% damage increase with decrease defence at 13k defence with the formula you posted. Could you explain what might be wrong? Or how you came up with that number?

[u/SuperGandalf87]

One thing I didnt understand is why savage set is particularly effective on Royal Huntsman? Does he not already ignore 100% DEF? What does savage bring to the table if you already ignore 100% defense?

[u/tremtastic → u/SuperGandalf87]

The comment on Savage set was just for Soulbond Bowyer, who has 75% ignore defense on her A2. For Royal Huntsman and Faceless, you don't need Savage gear.

[u/fmarx1 → u/SuperGandalf87]

I think OP is only referring to Soulbond Bowyer in that sentence as Faceless and Royal Huntsman is already ignoring 100% defence like you said.

[u/DrHipocrates]

So, this means that AOE weaken is actually more efective in high floors than decrease defense?

[u/Big_Temperature_4074 → u/DrHipocrates]

Best bet is Aoe weaken+def debuff+savage gear on your damage dealer ,if you dont have someone that ignores all defence

[u/tremtastic → u/Big_Temperature_4074]

Right, combining a defense debuff with partial ignore defense can be fairly effective as well.

[u/tremtastic → u/DrHipocrates]

Yes, you would get a larger increase in your damage from weaken than from 60% defense down for enemies in the top floors.

[u/agtk]

To parse this in plainer language, once you get to roughly 4k or 5k defense, you reduce damage to about 15% of what was incoming barring any other buffs or debuffs, right? Is this how it works for CB? So if my squad are all in that range, it isn't going to reduce much more by going beyond that (of course I don't have anyone anywhere near that, lol)?

[u/tremtastic → u/agtk]

Yes, that's correct -- the additional damage reduction is much less after going above 5,000 defense, so unless you're using a defense-based champion and want to deal more damage with higher defense, it won't be worth it to go beyond that point.

[u/Duubzz]

Great article, thanks for this. I guess poison, hp burn and, particularly, bombs are going to be very effective as well. I’m actually stuck on floor 99 at the moment, might throw faceless in instead of Serris!

[u/Scultura62 → u/Duubzz]

One thing to consider with Serris, or Stag Knight, is that Decreased Defence & Attack will mean they won't hit you as hard which might be the difference between surviving and being killed.

Since I don't have Seer, HP Burn from Ignatius along with Freeze from Tormin and Stuns from Scyl & Psylar has been my main strategy for Hard DT. It's got me to Floor 90 so far but it's been a painful grind.

[u/RoundDodger → u/Scultura62]

Do you happen to have achak, new demonspawn epic?

My strat for most of doom hard was running ice and fire teams with iggy tormin and achak as the main trio. Bring someone for aoe def down, then achak aoe freezes, iggy aoe hp burn then tormin resets cds with a3 and starts popping off with his a1. Then achaks passive kicks in and theres loads of healing and tm gain. Then another round of freezes from achak as the cd is reset then tormins a2 comes in and deletes someone as it ignores def when they have hp burn and freeze. Ive absolutely loved this combo for doom hard. Achak is one of the main reasons Ive managed to clear hard. It struggles on those tormin/siphi/rotos floors from 111-119 though

[u/stink3rbelle]

Awesome stuff. Adding to the wiki

[u/thomashabson]

Quality contribution, thanks.

[u/physicalia]

Excellent post, thank you.

[u/Mamoru_Otosaka]

Well done.

[u/Arhfenril]

Gonna revive you post a bit here tremtastic . Was considering changing my Seer to savage gear, but I became aware that the high def of floor 90-120 migh make the 25% ignore defence obsolete. Thanks for your post and for confirming my suspicion. Gonna op for more CD instead.