Hey guys, DC941 here. Today i’d like to write about Thornmail – an item with huge potential being frequently outclassed due to its mechanical and effective limitations. I will try to explain what Thornmail can do and why it can be a strong item choice under certain conditions, but also why Sunfire Cape is a better item in many different situations.
Thornmail really is a controversial item – only rarely bought in high tiers of play, it is generally regarded as a bad item. Ingame, you often hear “Buy thornmail and we win” in games where one team solely relies on physical damage; but even in this case, Sunfire Cape can outshine Thornmail; this can be explained with the principle of effective HP which I will try to explain later.
Thornmail vs Sunfire Cape – Pick and Efficiency
While both Thornmail and Sunfire Cape fill very similar roles (both provide defensive stats against physical damage dealers and deal magic damage to enemies), Sunfire Cape is still wildly more popular:
The interesting thing about this observation is that Thornmail on its own is by no means a bad item: the armor it provides would be worth 2000 gold, placing the passive at 200 gold due to the entire item costing 2200 gold. The armor and health of Sunfire Cape are worth 2088 gold in stats, making the cost of its passive 562 gold. The next thing we have to do to compare the cost efficiency of both items in terms of pure stats is looking into thornmails passive a bit closer.
It deals 30% damage to attackers based on their attack damage (and possibly critical strike damage) before damage mitigation comes in. That means that an enemy attacking a Thornmail needs to have at least 133 attack damage and enough attack speed for one attack per second or any possible combination with the same damage per second to receive the same damage that Sunfire Cape would deal in the same amount of time. While this is not a really high damage output for a marksman, it is for sure not possible to deal as much damage in the early stages of a game. This means that the passive of Sunfire Cape is stronger as long as it bought before the enemy reaches the mentioned DPS-threshold. The stronger the enemy attack damage output gets, the stronger Thornmails passive gets as well. The burning passive of Sunfire Cape also is surely not more than twice as strong in comparison to the thorn damage, making Thornmail the more gold efficient item – in terms of stats.
Another interesting point to note is that the passive of Thornmail can actually make the attacker receive more damage than the wielder: when the tank using Thornmail has 234 effective armor (armor with reductions and penetration taken into account), an AD-carry attacking a tank takes more damage than the tank – this is much stronger than Sunfire Capes static 40 damage.
Thornmail – Mechanical Limitations
After looking at the gold efficiency of Thornmail, one might stop and wonder why it so extremely unpopular. While its stat benefits look extremely strong on paper, Thornmail has a lot of mechanical problems which make sunfire cape stronger in multiple scenarios.
A first important point here is the functionality of both passives. The big advantage of Sunfire Cape is that its damage is constantly dealt around the user while not being limited by an enemies actions – many champions do mainly trade using their abilities damage in the early and mid game, notable examples being Riven and Renekton. These champions are not affected by Thornmails passive damage as much as they are by Sunfire Cape due to the fact that thornmail still requires them to autoattack. While it might work out fine against Tryndamere, pretty much all other top laners I can think of would not trigger Thornmail enough to make in a good buy for laning. In later phases of the game where teamfights happen, the mechanic of Thornmail is a double-edged sword: it can be more useful than Sunfire Cape if all five enemies autoattack the tank (it is very unlikely that you can keep all five enemies in range of Sunfire Cape); however, the enemy can also pretty much decide if they want to take damage from Thornmail by autoattacking you, namely the enemy support and ability-focused champions like mages.
Sunfire cape is also an important item used for splitpushing purposes. Its constant AoE damage provides a good way for tanky champs to melt down minions waves. Shen for example makes great use of the passive since he has no AoE clearing abilities in his ability kit. Thornmails damage depends heavily on the attack damage and attack speed of minions – and with both being very low, sunfire cape outshines thornmail for pushing until very late in the game since minions would need to reach the formerly explained damage threshold.
Thornmail and effective health
The biggest point in the comparison of Sunfire Cape and Thornmail probably is the principle of effective health. This system is based on the system of resistance stacking League of Legends: the more armor a champion amasses, the lower the effect of each individual point of armor is; armor is effectively a multiplicative factor for your health when looking at physical damage. This makes armor on itself only a good investment as long as the user increases his health to back it up. This is why the stat combination of Sunfire Cape is so very strong: it provides both health and armor, increasing the effective HP of a champion on itself more than Thornmail (in most situations) without focusing too much on either armor or health. It is quite difficult to math out the exact amount of effective HP gained just from Sunfire Cape due to its dependency on the other five items of the user and inbuilt resistances; Thornmail is gated in that regard due to missing strong pure health items – while Warmogs Armor could be a strong combo with Thornmail, the user would only really get tanky after buying both of them, spending a really big and important amount of money for two full items, which is problematic in the early and mid game.
The second big point here is that the health from Sunfire Cape also helps against magic damage and with building up effective HP against magic threats. Many bruisers deal magic damage with abilities (Aatrox “Blades of Torment”, Lee Sins “Tempest/Cripple”) and Thornmail does absolutely nothing to help against these (and of course nothing against casters).
Conclusion and notable users of Thornmail
The only possible conclusion from all this: Thornmail is not really an efficient item early in the game and on its own. It can however get really strong for its price with a fitting build later in the game. Some champions can use the mechanics of Thornmail quite well and I frequently get the item on them in later phases of the game.
Singed gains a lot of health from his passive, providing a good base for the high amount of armor Thornmail provides. He also works really well with Abyssal Scepter which amplifies both Thornmails and Sunfire Capes passives; Thornmail however is much easier to use on Singed since he can avoid enemy melee range quite well, only receiving damage from ranged champions where the burning of Sunfire Cape would not work really well. Singed does not really want to stay in melee range of enemies, making thornmail often a better buy than Sunfire Cape. Keep in mind that you still should have other sources of HP to back up Thornmail (Rod of Ages, Rylais Crystal Scepter or the likes) and that Sunfire Cape can be a good item if you are behind and you can not provide the needed HP with your gold income.
Elise is another noteworthy example of this as she works very well with magic penetration and bulk. The magic penetration from Liandry’s Torment, Sorcerer Boots, and the Magic Resist reduction provided by Abyssal Scepter make Thornmail stronger. Sunfire Cape is still a very strong buy on her though due to her sticking to targets in spider form. One could also try and get both Thornmail and Sunfire Cape on Elise to get really tanky if the enemy team is running double AD.
The common denominator here is magic penetration to make better use of the passive and bulk to amplify the effective health gained as well as Sunfire Cape not being 100% usable due to range mechanics. I don’t expect big changes from Riot regarding both Thornmail and Sunfire Cape and their places in very similar roles with different situational dependencies will remain like that. In the current state of the game however, it’s best for players to purchase Sunfire Capes earlier in games and reserve Thornmail for lategame scenarios and against heavy AD compositions.
UPDATE: With recent changes to sunfire capes damage, you should take this article with a grain of salt – while the argumentation about the advantages and disadvantages still is not wrong, the new damage scaling for the items fire aura brings the damage aspect of both items much closer together. The advantage of a HP+armor combination however remains.