Why do ADCs always go for damage over armor?

Question

Considering bot lane, it is customary for the ADC to build ONLY damage or armor pen while the support builds his gold income and sightstone. The idea behind this is for the ADC to be able to dish out as much damage as possible while depending on his support to keep him alive. I get this - it sounds reasonable.

What if you beleive you can last-hit just fine, you want to be able to trade well against the enemy, perhaps even win a 2v2 or 1v1 engage? Obviously as ADC you also would like to stay alive during a full engage, making hp or armor/resist a wish. What it comes down to is prioritizing, i get that. I also get that everyone seem to prioritize building only damage. I just don't get WHY. Say you go back as adc with 875 gold, so does the other adc. One of them buys a pickaxe the other one buys a chainmail and health pots. Once back in the lane, the fighting starts to break out. Let's examine the following scenarios:

1. Only the two adcs are present (both supports still at shop or for some reason just recalled). 1v1
2. All four bot laners are back in lane. 2v2
3. Disengage and continue to farm and harass

The defense adc can pop a potion just before the engage (chain mail being cheaper than pickaxe), effectly increasing hp as well. Let's also assume both teams target the enemy adc. The pickaxe adc will dish out more damage (+25) per hit, only to get it reduced by the armor (+40).

The way i understand armor is, that each 1 point in armor is increasing (effectively) hp by 1%. Making the armor a +40% hp. I'm aware this only works for attack damage, meaning any magic or true damage will go though as normal.

I'm aware the calculations are getting pretty hard now, so i'm gonna try and simplify it by assuming it's only a 1v1 adc/adc match. Also i'm assuming all damage from both sides is going to be pure physical since after all we are comparing a physical boost (+25 attack damage) to a physical defense (+40 armor).

Let's also assume both adcs are caitlyn (honestly it's easier and also my lol assistant listed her as free this week, making it easy to one-click and read stats). Let's assume they are both level 5.

(Effective) hp for damage adc: (390hp + (4 lvl * 80hp)) * (1 + (17armor + (4lvl * 3.5armor)) / 100) = 710hp * 1.31 = 930hp (Effective) hp for armor adc: (390hp + (4 lvl * 80hp)) * (1 + (17armor + (4lvl * 3.5armor) + 40 armor) / 100) = 710hp * 1.71 = 1214hp

Giving the armor adc an extra (excluding the healing pots) 1214hp-930hp = 284hp (it's equivalent to 710hp*0.4armor - just wanted to make it clear that i was factoring it all in)

Let's finish it up. 284hp/25 damage = 11,36

Without calculating the healing pots, the damage adc will win the engange if it lasts beyond 11 (atleast 12) auto attacks. That is a lot of auto attacks. Consider a normal fight - it should last less than that if you factor in the skills again (QWER) and also if you calculate the supports. Speaking of which. If supports are pure AD based, the favor obviously still swings towards the defense adc. If the supports are pure AP (kind of unrealistic since auto attacks should still be ad) then the formular still holds. The factor damage dealt/received by the two adcs would still favor the armor untill the 12 adc auto attack. Which will be even less likely since both supports are also focusing the adcs - making the engage last fewer turns.

I'm fully aware all this will chance once you factor in ganks, bursts, etc. I just wanted to review a pretty common scenario.

My calculations (if correct) shows that the early game would favor the armor adc - but i do understand the importance of building the Infinity Edge first. I just think getting the early kill(s) - if the armor adc succeed in capitalize on his advantage - probably would put you in a situation where you probably would still get there first, and this time also wearing a chain mail?

Am i missing something or are adc just blinded by a lust for more damage?

BTW, i main support, which is why i probably don't get the adc mindset...

Answer 1

There are two main reasons why you don't build armor as an ADC.

1st: The enemy Support as a target

Often you don't want to focus the ADC but also the enemy supporter (Let's just assume that it isn't a Leona or Braum but a Sona or Janna instead). Remember that about 70% of the Botlane work is done by the supporter. If you manage to kill the supporter (which is a lot easier if you already have bonus AD) the enemy ADC usually won't be able to do anything by himself vs 2. And like this you can snowball really hard, which is basically the thing to do as ADC.

Now of course you don't always want to focus the supporter and if the supporter is something rather tanky then don't even think about focussing him. So another thing you should take into consideration:

2nd: Your role in Teamfights

You are the Attack Damage Carry. The last word is the most important one. You bring the highest damage to the teamfight. If you waste your money on armor early on just to gain a small advantage for a small amount of time during the game, you won't be able to do your job right. Your jobs are Kiting, Positioning and Killing Whatever gets in range. If you build armor you just won't be a thread to anyone since ADCs heavily scale with AD and not with armor.

3rd: Farming

Well this isn't as severe as the other two points but... Farming is also a lot easier with more AD early on. You are able to lasthit better under the turret and with more Attackspeed you won't miss creeps that easily.

Answer 2

One thing you're not taking into account is that the ADCs aren't going to stand still, trading blows until one is dead. The C part of ADC is "carry", which means that the team is going to rely on them later in the game to carry the rest of the team.

The ADC, therefore, must make it its goal to deal as much damage as possible in as short a time as possible. If he can't deal as much damage as the opposition's ADC, he's putting his whole team at a disadvantage in team fights.

As a result of this, as you've noticed, the ADC doesn't have much survivability. This is why ADCs are classically known as "selfish" characters. Since they are so important to the team fight dynamic, but also so fragile, they often have to save themselves at the expense of other teammates either by not joining the fight or running early. Positioning is crucial for everyone, but especially so for the ADC; one step out of line could result in a team-fight-altering death.

So while the math may say that overall fighting ability goes up with armor in some cases, that's not actually taking into account the full spectrum of what the ADC needs to do. Hit and run tactics and focusing down targets in the mid-to-late game win out strategically over being able to tank the opposing ADC while you trade blows.

Answer 3

All the answers above seem to be valid, but everyone is forgetting another important point: scaling! Champions in League of Legends have these nifty abilities that often do damage, which is increased by a percentage of a certain stat. For ADCs, this stat is often Bonus AD (as in, AD that only comes from items, runes, masteries and buffs).

Lets look at Graves, first. His Q (buckshot) does damage in a cone, and scales off Bonus AD by 80-144%, in the case of a pickaxe that's an extra 25(.8) - 25(1.44) -> 20 - 36 damage every 10ish seconds. You probably won't get a second chance to back before level 6, so let's tack on his ultimate too: 120-150% bonus AD -> 30 - 37.5 damage. Put these in a combo, and you've got an extra 50 - 73.5 area of effect(!) damage. Hit 2 targets with each (or just one), which is not unreasonable, and all of a sudden you've gotten a lot out damage out of your pickaxe. This damage does get reduced by armor, but your opponent is only auto attacking you for ~50 damage at a time, while you're hitting him for ~40. The auto attack speed steroid that graves gets isn't even factored in here, and that gives even more benefit when you've purchased AD.

For a more common ADC, with no AD scaling, let's look at Tristana: She has a steroid called rapid fire, that at level 1 gives +30% attack speed for 7 seconds. With her q on, she'll get off about 5.9 attacks in the 7 seconds. Without it, she'll get off 4.6 attacks. If we use the same calculations of they attack for 50, you attack for 40, you do 5.9 * 40 = 240, and they do 4.6 * 50 = 230. Chain vest Tristana lost out on 10 damage! Keep in mind, though, that these "attacks per 7 seconds" calculations are done with BASE attack speed, and by the time you have a chain vest / pickaxe, the difference in damage dealt during the trade will continue to swing in the favor of the pickaxing ADC, as they'll have more higher damage attacks.

Armor doesn't work with any of the other stats that ADCs buy: life steal, crit chance (crit damage, in the case of IE), attack speed, Attack Damage works beneficially with all 3!

If the math hasn't convinced you, I offer you this: Do you really want a chain vest, pickaxe and bf sword while the other AD Carry has an Infinity edge? They're melting enemies with their 250% damage crits, while you're... dying slower and doing significantly less damage.

Answer 4

ADCs aren't sustained damage dealers trying for a deathmatch, and most of their skills are geared towards being a high damage glass cannon rather than a durable fighter.

During the laning phase, a Caitlyn (from your example) will try to use long range harass with Q or AA while trying to avoid damage altogether. If the enemy ADC comes into range, its the support's job to snare/block/shield/heal for her, that's why it is a dual lane.

Once past laning, in team fights Cait doesn't try to jump in like a tank, but will hover around the periphery dispatching targets from outside their range (a task in which she excels with her high AA range).

How does armor Caitlyn fare in either of these scenarios? Armor Cait will find it harder to harass an enemy support in lane to make them back earlier (thus forcing enemy ADC to be more defensive) due to her lower damage. If she manages to poke the enemy ADC, that will hurt less, so they can lifesteal it back faster. Lastly, she will have a harder time last-hitting mobs and may miss more CS, which is very important for an ADC.

Late game, that chain mail doesn't build into anything useful for her team fighting role. It doesn't give her tankiness to dive into fights, she will last maybe 1s longer while getting stun locked and unable to contribute. If she successfully stays outside enemy range, her actions will negate any benefit of having armor.

The quicker the ADC kills someone the less harm they do to your side ... so having an ADC who takes longer to finish off enemies is highly counterproductive to their main role.

As you can see, building damage is mandatory for an ADC to perform their role - they just cannot afford to ignore it in favor of other 'nice to haves' like armor. Hence why most ADCs need to go for risky builds and can only afford defense as a 5th or 6th item, since keeping up with the other ADC's damage is really important.

Answer 5

Teamfighting

AD carries are meant to survive in teamfights not through their HP/Resistance stats but due to their safety/range. As they also happen to be 25-35% of their team's damage output, AD carries must prioritize damage over safety.

Another reason for the prioritization of damage is because additional damage items scale your DPS non-linearly. Here's a chart I made for Jinx a few months ago (before AD carry item changes in Patch 4.10):

Note: Each differently colored line in this chart represents the first item bought in a traditional build path. This chart assumes a base attack speed of 0.625 and 130% bonus minigun steroid. Also, it is assumed Stattik Shiv procs every 10 autoattacks and deals damage to only a single target (25-30dps). Bloodthirster is fully stacked.

Let's look at the blue line (BT->Berserker's Greaves->PD->LW->IE) build path that was common in early Season 4.

9200  Gold:    480 DPS
13000 Gold:    930 DPS

In other words, a difference of 3800 Gold -- one item -- means a 200% increase in DPS!

This means that if you delay your build by buying resistances, at a certain point in the game the enemy AD carry might do as much as 200% more DPS than you.

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Laning

As a side note, lifesteal is a commonly built on AD carries. This means the more damage you do, the more effective health you have. Building armor early forces you to buy health potions or become outsustained in lane by the enemy AD carry.

Also note that enemy supports may be AP based (Leona, Sona) and enemy marksmen may also deal hybrid damage (Corki, Kog'maw). This means building armor may not even be of use in laning phase!

Answer 6

The above answers all raise very good points, but I want to expand a bit on what the previous answer stated. I know this question was from a while ago but I found this quite interesting. There are a lot of numbers below but at the end I've written a short piece actually answering the question.

In League of Legends items scale with other similar stats. What I mean by this is that the more armor you have, the more each point of health you buy will be worth.

For example, Say you have 100 armor and 2000hp at level 18 with runes and masteries etc. buying 50 armour and 500hp increase your effective hp (vs AD) from 4000hp to 6750hp, an increase of 1750 effective hp. Buying another 50 armor and 500hp increases your effective hp (vs AD) from 6750 to 9000hp, and increase of 2250 effective hp. As you can see, the second purchase of more armor and health gave more effective hp. This is because of the way that armor scales with health so building lots of both is more effective.

A similar thing occurs with offensive stats but even more so because there are 3 (4) stats affecting your dps, Attack Speed, Damage, and Crit chance (and Crit damage).

So if you had two champions, and they both built half offensive and half defensive, in raw total numbers they would have far less combat stats than two champions who had one build full defensive and one build full offensive. This effect is one of the reasons ADCs exist, because having a glass cannon style character and a tank will be stronger.

However in the actual game there are a lot of other points to consider, including abilities, positioning and the fact that when one character dies they stop dealing damage. Hence it is usually beneficial for the adc to build a defensive item (full build) and lifesteal to try and stay alive longer.

Aside from all the numbers above, the main reason you don't want armor early in my mind, is because once you get into teamfights you should be taking 0 damage (hence the armor is useless) and so want as much damage as possible. Your maths is valid and in laning phase I do think having defensive items actually is beneficial (especially in an adc 1v1), but it's not worth the trade off for being weaker in teamfights.

Answer 7

The way i understand armor is, that each 1 point in armor is increasing (effectively) hp by 1%. Making the armor a +40% hp.

It is true that

effective hp = (1 + armor / 100) * base hp

and therefore adding 40 armor will increase effective hp by 40% of base hp, but not 40% of effective hp (unless effective hp = base hp, i.e. armor = 0). That is, a champion's ability to take damage is increased by less than 40% by buying a chainmail.

Caitlin has 22.88 (+3.5 per level) armor, so 41 at level 5. Her standard rune page contains 9 greater seal of armor, adding another 9 armor, so she has about 50 armor before buying that chainmail.

That is, her effective hp without chainmail is

150 / 100 * base hp

and her effective hp with chainmail is

190 / 100 * base hp

so effective hp has increased by a factor of 190 / 150 = 1.267, i.e. 26.7%.

Now, what would the benefit of the pickaxe be? Let's do the same calculation for her damage output:

damage output = AD * AS + skill damage

skill damage for an adc also scales strongly with ad, so let's simplify this to

damage output = AD * (AS + c)

Cailyn has 50.04 (+3 per level) AD, so 65 at level 5. Her standard runes include 9 greater marks of attack damage, for another 9, and she probably has a doran's blade as well, adding another 7, for a total of 81 AD.

By buying a pickaxe, she increases this to 106 AD, i.e. her damage output increases by a factor of 106 / 81 = 1.308, i.e. 31%.

Therefore, a Caitlyn that buys a pickaxe will do 31% more damage than her clone who bought a chainmail, while the latter can take 27% more damage instead.

In terms of surviving a fight, the items are therefore about equal. However, having higher dps makes it harder for a losing enemy to retreat to the safety of his tower, increasing the likelihood of kills. It makes last hitting easier, resulting in a gold advantage. And it creates synergies with any attack speed, critical hit, or lifesteal items Caitlyn buys after that.

Therefore, an ADC is correct in not buying armor.