I don’t know of anyone using any troops with chance to dodge as their front line, but for the sake of this, we’ll assume it. Take a troop like Gorgotha. It has Granite Skin, 75% skull damage reduction.
If my Gorgotha has 75 Armor and 75 Life, it has an absolute health pool of 150 against Attack damage, all other things being equal (Doomskulls, Enrage, Hunter’s Mark, etc.) That means if the enemy does 70 Total damage from Skulls, it will be reduced to 17 damage. And 150 Health+Armor with 75% damage reduction from skulls also means Gorgotha has an Effective Health total of 600. That means he needs to take 600 damage before he’ll die – or approximately 9 attacks, each one doing 70 damage. That will result in 17*9 = 157, enough to kill him.
That also means that every additional Life or Armor he gets is actually worth 4, because he needs to take 4 damage total from skulls for it to count as 1 armor or life in damage.
Gorgotha is a Defender:
The total life+armor he would gain from being upgraded to gold is 24 (4+8+12). Remember we are treating Life and Armor the same, because Skull Damage rarely has “True” damage (only 12 troops have Armor Piercing which is a 50% chance to ignore armor with skull damage, and only 1 troop, Orion, has True Shot, which is a 75% chance to ignore armor).
That 24 Armor and Life is much more valuable to a troop with skull damage reduction, because remember that for Gorgotha, each point of life or armor is effectively worth 4, which means adding 24 is really like adding 96. It means he can take 96 more damage from skulls before dying, not just 24. And for Stonehammer? His 80% means each point is worth 5. Upgrading him to Gold is like giving him 120 more Effective Health (AND he can gain life himself!)
In fact, there’s a whole bunch of different skull damage reduction talents in the game:
…but what about troops with Dodge chance? Well, a whole bunch of troops have a 20% chance to dodge. And a number of classes with the Cunning talent tree (Archer, Assassin, Corsair, Dervish, Thief, Warden) have access to 30% chance to dodge. Artema even has a 40% chance to dodge, the highest in the game, with her trait Dexterous.
So what’s that mean though? Well, in our previous example, Gorgotha had 150 Health+Armor and was taking 70 skull damage, which was reduced to 17.
If instead he had a 20% chance to dodge, then statistically, he’s going to get hit for 70 four times, and dodge one time. That’s 280 damage he’ll take. If he dodges the first one, it’s likely he’ll die in the next three attacks against him. So what would his Dodge actually need to be to be comparable to 75% damage reduction? Well, if 9 hits kills him with 75%, then we need a chance to dodge that will also have him survive, on average, for 9 turns.
To make it easier, we’ll increase the skull damage to 75, which increases the damage taken to 18, which reduces the turns till dead to 8. An even number is easier to work with
With 8 attacks, we’d expect 20% dodge to save us about 2 times and fail us 6 times. That means we’ll take 450 damage total. That’s way too much. We’re dead several times over. At 30%, available to Hero classes, those numbers change to 3 and 5. We survive one more attack, that’s it, but that’s something – that’s 75 damage more we dodged!
But in fact, we need to pump the dodge chance up to a ridiculous 70% in which 6 attacks are dodged and 2 hit us for 75 each and we die.
What about medals then? Well… as a matter of fact, a TON of troops that have chance to dodge don’t even get life or armor from medal upgrading, because they are classified as Assassins and Mages. Lots of people run Umenath in front because of Eagle Eye and Huntress talents, but he only gets Attack and Magic from upgrading. Is that good though?
Actually probably YES! If he gained the same 24 Life and Armor that Defenders gain, he would only survive longer than the number of statistic hits required to kill him. That is, in our scenario, Gorgotha has 150 total life and armor and he gets attacked 8 times with a HUGE 70% dodge chance. The two times that he doesn’t dodge the incoming 75 damage, he will die. But upgrading him and adding 24 life and armor won’t help him very much at all. Why? Because statistically, he’ll probably dodge that “9th” attack, but he won’t dodge the 10th attack (or you could flip those around). That means he’ll take 75 damage three times (10 attacks and he can only dodge 3 of them, on average). That 24 extra health and armor saves him for only possibly 1-2 more attacks, on average.
But for the ACTUAL Gorgotha, the 24 extra life and armor really is 96 more effective health against skull damage, and that incoming 75 skull damage, getting reduced to 18, means he can -definitely- survive more hits. Why? Because we have an effective health now that is higher than the incoming damage. That means there isn’t just a chance we will survive the next attack, we -always- will. 75, after all, is less than 96.
That being said… we’re definitely toast after that.
So why don’t we see troops with higher dodge chance? Well, probably because dodge is super frustrating to play against. While “statistics” say that we’ll survive X number of attacks, in reality, there are super weird streaks.
I’m sure you’ve all fought against Infernal Kings that just. won’t. die. You’d think 25% would be a really low chance, but I have had multiple occasions where he comes back 5 or more times. After all, every “chance” is completely independent. Him resurrecting once doesn’t have any statistical meaning on his odds the next time. It’s still 25%. Of course, I remember the times when we does it five times in a row and I forgot the times he dies and doesn’t come back the first time…
And that’s exactly what happens with Dodge, and every other “chance” ability. While statistically Gorgotha would need a 70% chance to dodge to be on the same level as his 75% Granite Skin talent, that will never happen, and there’s a reason the dodge chance is only 20% for troops (with one exception for troops and a slightly higher chance for some classes): because any higher and it becomes painfully annoying when the odds are either against you or for you (depending on what team you’re on…)
It’s a lot easier to understand in fact when you strip the numbers down to bare survivability of one turn.
Let’s say your first troop has 50 Life and the enemy has 50 attack. Your troop has the lowest damage reduction available: Thick Hide, 20%. You can survive for 1.25 turns, because you have an effective health of 63. You know the 50 damage will only do 40. But then you’ll only have 10 Health left, and 10 Health doesn’t survive another hit of 40. Or you can take 20% dodge.
Which one would you take? Personally? I would take 20% skull damage reduction every time. Why? Because with dodge I have an 80% chance to instantly lose my troop, no matter what. With skull damage reduction I am guaranteed to survive one turn (but not two).
…but what if you had 51 life? o.O In that scenario, suddenly 20% dodge looks kind of okay. That extra 1 health means you will always survive the first hit if you miss your dodge, but it does nothing for the skull damage reduction.
To survive two hits with the 20% skull damage reduction, you’d need 81 health. With that, you’ll always survive two skull hits, but with dodge, you will only survive the first one guaranteed, the second one might kill you.
As should be evident then, gaining life and armor with skull damage reduction becomes better and better the higher the reduction is, because you need less life/armor to survive attacks. The same isn’t true for dodge, because dodging only guarantees you survivability for as many turns as the damage divides into your life+armor. After all, you might dodge nothing!
If you’re ever wondering why more troops don’t come out with higher dodge chances, this whole super long explanation is why, and it’s also why troops with dodge are never Defenders – but some are generators.
Generators with skull damage reduction cap out at 50% – all the 65%+ ones are Defenders, against for Borealis who is a Warlock (and Warlocks still get Life and Armor, they just don’t get as much Magic from upgrading as Assassins and Mages do).
This all is also why I have fully upgraded one of my favorite Defenders: Glaycion, and I’ve upgraded Stonehammer to Bronze. Upgrading your Defenders is a smart investment ;-D