Locket of the Iron Solari vs. Aegis of the Legion - what's better in a teamfight?

Hello, hello! DiffTheEnder with you again and coming off the back of that surprisingly popular article on Thresh, we head into another support themed article on what's more effective in a teamfight --- the Locket of the Iron Solari's shield or the Aegis of the Legion's persistent armor/magic resist aura. This is something that casters such as MonteCristo have been known to ponder during games and we'll get to the answer of this question by the finish of this article. (And yes, that was a Deman reference <3)

So without any further ado -- let's dive in!


Firstly, what do these items do?

At the very core - these items are both items intended to be carried by a support champion for the benefit of their teammates. Both of these items' purposes is to increase the durability of your teammates - either through the Locket's activatable shield or the Aegis's persistent resist boost. Let's take a look at Aegis of the Legion first, the more popular item.

A steady boost of armor and magic resist with some health regeneration to boot. We'll run through these in a bit more detail after we take a look at the shielding beacon that is the Locket of the Iron Solari.

A flat value shield that scales on the item holder's level. The above screenshot was taken with a Level 14 support as you may have realised. It seems fairly weak at first glance - but mathcrafting will prove that first impression wrong.

An important question that must be asked is - what is the range of the aura or the shield active? Well, here's the answer in picture form, with the Flash radius included for comparison purposes (everyone knows Flash range.. or at least I hope!)

The core of the analysis -- teamfight potential

The focus of this analysis is the benefits for your teammates in a teamfight. We'll completely disregard statistics for the item holder at the time being and just take a look at the Aura vs. the Active. We can further simplify our comparison of the Aegis's aura and the Locket's shield by ignoring the health regeneration portion of the aura. Health regeneration of such a small value is of little significance in a teamfight - considering skirmishes do not last very long. If you're worried I'm oversimplifying this calculation - do not fear, I will talk about the benefits for the item holder among other things after the math is done :)

So now that we've cleared up the basis of the comparison - let's math it out. Is an X value shield better than a 10 armor, 15 MR aura boost?

The Math - Health, resists and effective HP

There are a few factors that must be understood to go about this calculation in a methodical way. 

  • Effective HP is the value of your base health multiplied by each % of resist that you have. This explains it fairly well.
  • Resistances scale with HP
  • HP scales with resistances

In simpler terms, Aegis provides resistances - this means the more HP you have, the better it is. Locket provides a shield (temporary boost in health) - this means the more resistances you have, the better it is. That's the underlying concept that can and will be proven.

An Aegis provides an average 12.5% increase in your EHP due to the resist aura. (10% armor, 15% magic resist) - that's the simple calculation. 

The Locket of the Iron Solari however is a much trickier beast. It gives you a shield, which is a temporary boost in Health. "Great, I have more HP!", you might say. Here's the cool part, shields scale off resists as well. So a shield of 200 on a Malphite (high resist champion) will usually be stronger than a shield of 200 on an Ashe (low resist champion).

The Locket gets to "double dip". It provides HP that scales off resists; and this means that the effectiveness of the Locket is based on how much resistances you have.

For the sake of the readers, I won't go into creating contour difference plots (rainbow graphs) as I have been known to do and I'll instead present the data to you in the form of a few tables. It's easier to explain the table once you've seen it. So let me just drop one right here.

DiffTheEnder, you've gone too far, what is this monstrosity of a table?

We'll break it down column by column

  • 1st column - the support item's holder's level
  • 2nd column - how much the Locket shields allies within the active range for
  • 3rd column - the HP you have at said level. (Base HP used for Ashe and Blitz, meaning no extra health built at all)
  • 4th column - your HP plus the shield amount
  • 5th column - Your Effective HP with Aegis (12.5% multiplier)
  • 6th column - This is the pièce de résistance. This is the average value of resistances ((Armor + MR)/2) you need for Locket to be more effective than Aegis. E.g: In the above table, Blitzcrank with an average of 16 resist will always benefit more from a Locket's shield than an Aegis aura.

But if Blitzcrank, pretty much always benefits from Locket, should I just rush Locket now?

Don't jump to conclusions yet! Remember what I said about the more HP you have, the better Aegis gets? Well, if Blitzcrank builds some HP items or has some HP scaling runes or masteries, he might have anywhere up to 3000 or 4000 HP by level 18. How much resistance do you need when you have that much HP to outscale Aegis? Take a gander below.

And now you're seeing some more competitive values where Aegis starts showing that it is not a trash aura compared to Locket. However Locket will have the edge in most realistic situations even now. Let's take a look at an even more extreme example of a champion like Cho'Gath or Olaf who might stack HP to something like 4000 HP benefits from a Locket vs. an Aegis.

You will realise that the HP at each level have been arbitrarily assigned to show a realistic increase in HP as the game goes on. However even in this scenario, Locket will have an edge in most realistic situations. Having an average resistance value of 117 is not as high as you might initially think. Keeping in mind that most champions that have 4k HP will be 170+ Armor late game -- they'd only need 65 MR for Locket to be more valuable to them.

So it seems Locket of the Iron Solari is in most realistic situations the more valuable option based on pure numbers. But for another extreme example - let's take a look at Ashe. One of the lowest base HP champions who very rarely builds any HP items. This is a realistic representation of her in-game HP.

No that is not an error in my Excel formula. An Ashe who does not build HP, can have both of her resists penetrated to zero and she will still benefit more from a Locket than an Aegis. 

So at this point, if you've actually read through everything till now, you'll be thinking, "Wow, Locket OP, must rush every game". I'd advise you to read the next sections before making that decision.

Other Factors to Consider

We've proved that in nearly every realistic situation, Locket either matches or outdoes Aegis in terms of shield vs. passive resists. However, there's more to the tale than just that.

  • Locket's shield only lasts 5 seconds - What this means is, you have 5 seconds of time where Locket may be effective, if you don't get damaged in that period, it's wasted.
  • Frontloaded vs. sustained negation - An Aegis aura benefits you at all parts of a fight, however Locket negates the next chunk of damage you're going to take. The above calculations about "needed resists" is only true when you have an Aegis aura affect you for the full extent of your HP. i.e. While you go from full HP to death, a support with Aegis is standing next to you the whole time. An Aegis aura may not be present due to a support's death or positioning issues. However a Locket's shield is usually fully utilised with proper use of the active. +1 for the Locket in my opinion.
  • Poke damage - When you're dancing around Baron or pushing for a tower, your team takes a lot of poke damage. A Locket is of no use in negating poke as you'll never the active to negate skills like Nidalee spears in 99% of situations. +1 for Aegis.
  • Gold use and Runic Bulwark - Aegis and Locket cost around the same. Locket has no upgrades but Aegis does. The Runic Bulwark provides an extra 15 MR to the team in addition to the Aegis aura. How does this translate to the "Needed resists" -- approximately double the resists. If a Blitzcrank needed 15 average resist like in the example above for Locket to beat Aegis, he'd need roughly 30 average resists for Locket to beat Bulwark. However this does come at an extra cost of 950g. Are you willing to spend money for this?
  • Benefits for item holder - Does your support champion need the magic resist at all times? Is there a lot of magical poke? Go for Aegis. Is the magical poke not that severe? Go for Locket. What the Aegis gives in MR, Locket replaces for what is in my opinion a more beneficial stat for supports, the almighty Cooldown Reduction, which allows for more heals or CC as needed, MR or CDR? Your choice.
  • The Solo Queue Player - Sometimes you'll get the gem of a player who rages because his support built a Locket instead of an Aegis. Is it worth having a slightly better item for having an angrier teammate? Maybe.
  • Health regeneration - The first thing we did in today's analysis was ignore this as it wasn't significant in a teamfight. But here's a question you have to ask yourself - would you be buying a Locket or an Aegis early enough in the game to benefit laning phase? Health regeneration and passive resists are much better in extended trading situations like laning or even late game lane pushes. 
  • True damage - A Locket is infinitely better than an Aegis when negating true damage such as Ignite or DestructoDarius. Resistances do nothing to negate True damage.
  • Your Champion - Are you a champion who gets in the middle of a fight to get your important skills off and may die quickly? Eg. Leona/Thresh. It would be more beneficial for you to buy a Locket as you can activate its benefits before going in to potentially die whereas with a champion who is more focused on auras and staying alive, e.g. Sona/Janna, will benefit more from an Aegis (but still not as much as Locket in a teamfight)


 A well timed Locket shield in a teamfight will, in most realistic situations, benefit your teammates more than an Aegis will. However, Aegis provides more suitable attributes over extended periods of trading, i.e. laning phase or team pushes. There are several factors as listed in the previous section to account for when choosing the item to build.

If you ask my opinion, I'll be rushing a Locket of the Iron Solari over an Aegis of the Legion due to the fact that a shield is front loaded, has no reliance on whether the support is near you or dead in a teamfight and is stronger. You can also bait with a Locket similar to a Barrier! I highly recommend having one Locket and one Bulwark/Aegis on your team instead of two of the same auras.

In the end, the decision is yours and the math is done for your decision making purposes. Choose wisely and above all don't rage at your teammates!



If you enjoyed this analysis - I'd appreciate your support in helping spread the word about Locket!

If you guys have any questions, feedback, suggestions, propositions or anything else you'd like to say:
- Feel free to join me in the "A DIFFerent View" chatroom on the NA server in the LoL Client
- Leave a comment on this post
- Email me at [email protected]
You can find all my articles/posts from the old Reign of Gaming here



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