Getting the Most out of ADC Effective HP

Introduction to Effective Health

There's a popular misconception floating around that if the enemy team starts building a lot of percentage armor penetration, you need to build more health. Why would you invest in armor when that Kha'Zix reduces 25% of it with his Black Cleaver and then penetrates over 35% of your remaining armor with a Last Whisper? You get so little real armor from your armor items that the real secret to surviving burst casters is building more health. Right?

Well, that's not very true. As I'll discuss in this article, what you should really be concerned about is your effective HP. It's your EHP that determines how much damage you can sponge before you die, and it's related to both health and resists; they complement each other. Stacking health without gaining armor means that each point of health is quite ineffective, and stacking resists with a low health pool makes each point of health effective but you have fewer of them (incidentally, SivHD's Potion Master Garen relies entirely on the concept of EHP). Because of how the equations work out,

HP IS COUNTERED JUST AS HARD BY PERCENT PENETRATION AS RESISTS THEMSELVES

It makes sense when you actually think about it. Simply by ignoring a portion of your armor, each point of health you have sponges less damage. So building health becomes less efficient by the existence of arpen. Of course, the same thing can be said of magic resist and magic penetration, but I often see this argument in response to AD midlaners.

So wait, what is the point of this article? Most of my musings revolve around AD carries (mostly because they're the most controlled environment. Their base stats vary very little and they have relatively few itemization choices, so they're far easier to compare than top laners or junglers for instance). An AD carry will usually only have a single slot to allocate to a defensive item - usually Guardian Angel. I realize that the passive is useful, but are there viable item alternatives that could be considered against a bursty AD team?

Could it be that the revered Guardian Angel isn't perfect in 100% of situations?

Fairly Ugly Mathematics (Read if you Dare)

The basic equations for effective health are not too difficult. At 0 armor and magic resist, your effective health is equal to your HP and then is increased by 1% for each point of resists you have. Formalized, that's merely:

 PhysEHP = HP * (1 + Armor/100)

MagEHP = HP * (1 + MR/100)

The point of this article is to find the amount of bonus EHP that each defensive item would provide to an AD carry, so the above equations need to be changed so that they can show the change in EHP by adding health or resists. Furthermore, I'm interested to see whether penetration items on the enemy team change the "ideal" defensive item, so I also added flat and percentage penetration into the expressions. Rather than bore everyone with a step-by-step walkthrough of the algebra, I'll just summarize and present the final equations as truth.

Overall, this equation is just used to generate the Excel numbers in the later sections, and the ambitious could also use it to get maximally tankier in other lanes/roles. If you inspect the terms though, you can see why health is countered just as hard as armor is by percent penetration: the "1 - %Arpen" term is multiplied to both the armor and HP terms inside the huge parentheses. The final term also points out the main difference between %arpen and flat arpen: flat penetration makes flat health more inefficient while scaling penetration degrades the value of your health pool.

But the next step is to get the BaseHP, BaseArmor, and BaseMR values for the equation by figuring out stats a standard AD carry would have.

Meet our Hero, the Most Average ADC in the World

To get a standard value for health, armor, and magic resist for an AD carry, I averaged the stats at level 18 for the thirteen main ADCs. I then assumed:

• Additional HP Sources
• 30 HP from Veteran's Scars Mastery
• 108 HP from Durability Mastery
• Additional Armor Sources
• 6 Armor from the Hardiness Mastery
• 10 Armor from a teammate's Runic Bulwark
• 12.69 Armor from nine flat armor seals.
• Additional MR Sources
• 2 MR from the Resistance Mastery
• 30 MR from a teammate's Runic Bulwark
• 24.3 MR from nine scaling MR glyphs.  

This means that the most typical AD carry in the world would have 2010 health, 101 armor, and 86 magic resist at level eighteen. These are the values I'll be using for the EHP calculations to come.

The Raw Charts

A lot of plugging and chugging later, I came up with two huge charts for "how much more EHP does this item give me". The items ranged in price from 1660g for Quicksilver Sash (listed on the charts as Mercurial Scimitar, but the upgrade doesn't improve its defenses at all) up to 3300g for Frozen Mallet.

In some cases, there were actives and passives to consider that provide bonus health or shielding. These three items have two entries each in the tables depending on the cooldown status of the active/passive.

• Locket of the Iron Solari's active provides up to a 230 point shield to yourself and allies on a 60s cooldown.
• Guardian Angel resurrects your champion at 30% of their maximum health every 5m. For our typical AD carry, that's 600 extra health. 
• Maw of Malmortius gives a 400 point shield against only magic damage every 90s. Notice that since this shield only works on magic damage, the active only improves magical EHP. 

The charts look more intimidating than they really are. There are four big groups on each chart, with each group representing how much penetration the enemy has that's hitting you. After all, armor will give less EHP against a BC/LW enemy than it would against an itemless enemy. 

Physical Effective Health Increases

Magical Effective Health Increases

The Infallible Guardian Angel

Frankly, I don't think that any numbers I find or statements I make will convince many people that Guardian Angel isn't the defensive item they'd want on an AD carry (except for those times when QSS is sorely needed). People just really like the passive, the insurance policy against dumb positioning or being focused hard. The argument certainly has merits. 

1. Guardian Angel offers both armor and magic resist, being one of only three items in the game that offers mixed resistances. The advantage to increasing both EHPs via resistances rather than building more flat health is that lifesteal is more effective. Each point of returned health is worth a lot of effective health so you increase your sustained survivability by building GA.
2. You have overkill protection. That last move that pops your GA? It doesn't matter if it's a 40 damage autoattack from the support or a 600 damage Karthus ultimate. All the extra damage that goes into popping the passive is wasted rather than further depleting your post-resurrection health pool. 
3. Redirects focus. The two or so seconds that you spend resurrecting after the passive pops can sometimes be enough for the enemy team's focus to redirect to another target, giving you a chance to take advantage of the confusion as a big damage dealer re-enters the fight. Buying other defensive items still means their bruisers may chase you until you're dead, end of story. 
4. Hampers the reset. This may be niche, but some teamcomps rely fairly heavily on getting resets from kills or assists. The same two second delay that redirects focus also prevents champions like Katarina and Master Yi from getting their damaging moves to come back off of cooldown via resets, and that can sway the fight heavily in your favor. 

Of course, there are also some drawbacks. It's ultimately up to the reader whether these constitute a compelling enough argument to consider the other defensive options. 

1. Building mixed resists over health increases the value of your lifesteal, but also makes you more susceptible to true damage. Irelia, Vayne, Cho'Gath, Darius, Olaf, and others all deal significant true damage, and frankly, even red buff adds up quickly over time. Defending against these damage sources would be better accomplished with health.
2. Guardian Angel only really makes you tanky if you include the 30% health on resurrection into the calculations, which can only happen every five minutes. The charts above show that in terms of physical defense, GA with the passive down is in the lower 40% of the defensive item options and is more or less the worst choice for magic resist. The values are good when the passive is up, but that's not entirely reliable. For perspective, a Karthus with a Void Staff would only need ONE more Lay Waste to kill you with a no-passive GA compared to a pure glass cannon AD.
3. That resurrection has the potential to be really awkward. I've seen many carries get caught, have their GA passive popped, then resurrect to five enemy champions camping their corpse. Then the passive (which is really what makes GA strong to begin with) is down for the next crucial teamfight. Or sometimes the passive triggers midway through the fight but all your teammates are dead by the time you resurrect. Or even if you're zoned out of the fight by a high damage bruiser and then lose your duel, you'll probably be camped on your spawn. Yes, it's dependent on who you're playing, the skill of the player, and whether your escape abilities are up, but it's undeniable that sometimes the GA passive nets you nothing in the teamfight. It reminds me of the common argument against building tenacity on ADCs: if you're out of position enough to be CC'd, tenacity won't save you.

So here's where I get contentious. I'm going to (gasp!) suggest alternatives to Guardian Angel. 

Randuin's Omen

The main appeal of buying Randuin's would be unmatched physical defense. No other item will give as much defense against physical damage dealers for an AD carry. The combination of high armor and high health makes Randuin's a potent defensive item. If you're getting bursted down by an AD assassin or their mage was crippled early game and doesn't deal relevant damage, Randuin's may keep you alive better than anything else in the game. Randuin's offers 200-300% more effective health than a GA with the passive on cooldown, and even out-EHPs Guardian Angel when you include the 30% HP on resurrection. This is true whether the enemy has stacked penetration or is just rocking a Last Whisper and nothing else.

In fact, the 500 flat health on Randuin's also makes it offer better magical defense than a Guardian Angel with the passive on cooldown. While not something I'd recommend when facing a heavy AP team, Randuin's gives about the same magical tankiness as a Quicksilver Sash would - nothing to scoff at.

Randuin's also gives quite good dueling and kiting capabilities. Merely attacking you causes the enemy to get a 20% AS debuff and a 10% MS debuff which should make right click battles with the enemy AD carry goes entirely in your favor. The active (once per 60s) can also provide limited self-peel in a teamfight. Pop an AoE slow and kite away raining pain and death upon your foes.

There are, of course, disadvantages. Randuin's Omen costs 3100g, putting it on the more expensive side of all the considered items and 500g more than Guardian Angel. The increased health pool also makes lifesteal slightly worse (but while making true damage less painful). Overall, I couldn't recommend this if you're against AP assassins, but against bruisers and AD mids this is a really undervalued item.

Summary: The BEST item for physical defense in any situation, an amazing active and passive. Make sure you can afford it and don't build it against multiple AP comps.

Locket of the Iron Solari

Another item that stood out for me, Locket is fantastic if you reliably remember its active. For a mere 2000g this item is one of the least expensive on this list. If you reliably sponge damage with the shield active, Locket gives top tier physical defense and as much magic defense as a Quicksilver Sash would - both higher than a Guardian Angel without the passive. Other benefits are that Locket gives this 230 point shield to your entire team (although if other teammates have Lockets, repeated actives within 8s are only half as strong) and provides hard-to-find CDR for an AD carry.

The disadvantages, in my mind, are that a big portion of Locket's tankiness comes from remembering to use the active. With the burden on the player its much more error prone than the automatic trigger of the GA or Maw passives. Additionally, if money is no option then there are better choices. Locket of the Iron Solari seems strong for an AD carry that is a little behind and starved for cash, not one miles ahead with gold to spare.

Summary: Very EFFICIENT item for tanking that offers CDR too. Best on poorer ADCs and not good if you forget the active or are against multiple AP comps.

Warmog's Armor

Yes, it sounds a little silly. But since it emphasizes health so strongly, Warmog's gives very high physical and magical EHP and gives the best mixed tankiness out of any item. It's also only 50g more expensive than Guardian Angel. That said...

I don't actually think Warmog's has good synergy with the AD carry role. Massively increasing your health pool hurts the value of lifesteal significantly (moreso than the other items on this list that offer half or less of this amount), and the passive is catered more to high HP monsters who sustain back up between fights instead of damage dealers who depend on sustain to be able to stay in fights the entire time. It just seems like an item for a different role to me. Maybe it could work with a non-lifesteal based build path, but that'd be a topic for another day's musings. 

Summary: Probably a good buy if there are both AD and AP assassins on the other team that threaten to burst you, but the lack of a worthwhile passive and non-synergy with ADCs make other items a better buy in most cases.

Magic Focused Items

Now I take a shortcut and lump all the magic resist items together. Honestly, I haven't been seeing many AP heavy team compositions lately, and I think most of the champions that dive onto AD carries or otherwise present unavoidable damage are attack damage based, so armor shouldn't be dismissed lightly. In most cases, I think the classic Guardian Angel is enough insurance against magical burst or one of the armor/HP items like Randuin's or Locket (discussed above). 

Now if you're really that terrified of the AP damage on the other team, there are options. 

1. Quicksilver Sash / Mercurial Scimitar is a requirement against some team compositions. If the other team has suppression or can easily pick you off with chained hard CCs, then the active on QSS/MS is more important than any amount of tankiness than other items would provide. Some players also just prefer this over beefing up, like the ADs that run Cleanse on absolutely everyone. 
2. If the damage and MR of the Mercurial Scimitar appeal to you but you don't need the active, then Maw of Malmortius offers entirely better magical defense because of the 400 point shield, as well as higher attack damage for most HP values. It's a great item, assuming you're not worried about their AD threats or crowd control.
3. If you want some mixed defenses but just want to focus more heavily on the magic side of things, Banshee's Veil and Runic Bulwark seem the strongest options. Banshee's has the side benefit of the spell shield (which can either block a huge damage spell or a measly poke depending on how careful you are) and is quite inexpensive at 2500g. On the other hand, Runic Bulwark offers the best magic defense in the game (because of the combination of the health and magic resist) along with solid physical defense, but lacks any utility that the other items in this discussion bring. 

Summary: Magic oriented defensive items are far more situational. Usually you're better suited going with the Guardian Angel staple or an armor item unless you need the cleanse active on Quicksilver Sash or are greedy and want the bonus damage on Maw of Malmortius. 

Conclusion

The long awaited tl;dr for this massive essay. For AD carries, Guardian Angel just doesn't make them particularly tanky when its passive is down; the effective HP bonuses it grants are lower than the vast majority of other defensive items I examined. The only reason to build Guardian Angel (big shocker right here) is if you need the resurrection. 

If your personal experience says that you usually die instantly after coming out of GA, then you may be better served by building Randuin's Omen (super strong anti-AD item, useful every fight instead of every five minutes, matches GA for magic defense) or Locket of the Iron Solari if you're poor and need to catch up. Most of the other items I looked at seemed quite niche or didn't have impressive EHP numbers compared to these options. 

So yeah. As crazy as it sounds, try building Randuin's Omen or Locket of the Iron Solari on your AD carries. There are some definite upsides to both, and the only way we can continue to evolve this game is by going out and actually trying new things.