Thornmail is no longer countering AA's since its nerf. You need 600 armor to achieve the same result as previous version which is extremely rare. This item has lost its effectiveness.
If you want this to counter AA only then you will need to increase the scaling from AA. If you want this item to be more utility based rather than passive then add an active that doubles the scalings with decent cooldown.
bad manner kid34 votesOne vayne died to one Thornmail before worlds, gg Thornmail.
ayNigerianPrince10 votesThat was satisfying to watch.
iamthegoatofwar7 voteswait did an lcs player die to thornmail and it got nerfed or something...is that what happened?
Zero Engine3 votes[deleted]
iamthegoatofwar8 voteshonestly can you not be an asshole about it...i was asking a serious question...
Zero Engine6 votes[deleted]
ayNigerianPrince8 votesThe fact that Vayne died to the thornmail was hilarious enough, only for it to be a denied penta with the target one aa away from death. Just perfect.
BeatzBoyFTW1 votesThe pain of losing a penta to a Thornmail. Now that just su-
Oh wait, its a Vayne. Lol, suck it xD
crunchymunchys6 votesPlaying a tank is a joke unless its a juggernaut. I remember when every game had a tank and adc's did fine against them hell most of the time teams had 2-3 tanks and this was before vayne. It was slightly slower yes but at the same rate the tank was a threat to the back line who usually didn't build resistances. Now building resistances is almost a laughable joke. Thornmail was a hidden king for so long its sad to see it die just because riot doesn't like how tanks slow the game down. Also why keep the two damage kill scaling items but remove the health one because its passive was op? The health at the time wasn't even better than warmogs and when did you see a tank go 10/0 in a game back in season 2? Botrk has been the best lifesteal item since season 4 simply because it just deals the most and heals the most damage when it comes down to what adc's do the most autoing. The lifesteal after a recent change where the hp% heal back was buffed made it so that the item countered thornmail before they changed the item. Nerfing Armour because of 4 champions you decided to release overloaded like usual is just down right insane. Also whats up with all the hp% true damage or armour ignoring champs now. GP ignores 50% of your armour, Cait can ignore a large part of armour on certain auto attacks. Vayne has always done %hp true damage. Seriously why does this game have to have so much true damage? Yet you go off and nerf things like armour to make sure that no one would ever want to pick it up because tanks slow the game down and fights might last more than 5 seconds. Guess we should of saw it coming when turrets no longer did damage past level 6 though so our bad right?
RisenDarkKnight6 votesYeah armor scaling is silly because if the armor scaling is at all high, supports/mages/other tanks will take more damage than they deal trying to auto you, while it still won't be very effective against adcs. Sure it is weird that thornmail counters adcs who are doing well, but they can always build magic resist/bloodthirster. Now thornmail doesn't really counter anyone, because the reflect damage is pretty low, it leaves you highly vunerable to magic damage/true damage since you are paying 2300 gold for only armor, and most champions can avoid autoattacking you unless you have a taunt.
LadyRenly6 votesWhoever thought it was a good idea to change thornmail, well, it wasn't. I only built thornmail as an armor alternative to make a high AA comp regret it, and then maybe buy a bunch of health or maybe some other armor, but forcing it to need more armor to work well...uggh.
Silents4295 votesIt isn't suppose to be a counter to auto attacks.
And I can feel the downvotes now, but it's meant to add more DPS to tanks, not to make you immune to an entire roles primary damage output, that's just crazy.
TurquoiseYoshi8 votesIt's supposed to make ADCs think twice about attacking that tank. It makes ADCs have to think, instead of just sitting behind everyone, AAing everyone for all the damage.
Silents4292 votesIf you think the entirety of the ADC role is sitting behind his allies with a thumb up his ass then you need to broaden your play. Tanks are suppose to be kitable, not a big middle finger to the ADC for defending themselves.
It's meant to give some extra damage to their already lackluster damage, not outright kill marksmen.
Blue Moon Wolf4 votesand let's not forget the all the lifesteal items that I never see any AD champs that plan on doing any amount of damage go without. I hardly ever see an ADC not grab 
as soon as they can. Now with the 
nerfs, getting BT is just overkill. Honestly I just get 
and 
now. gives more armor, more health, a speed boost AND I do magic damage in an AOE that way.
Mecha MaIphite4 votes600 armour?
Easy.
xxxMadLionxxx3 votesIt suppose to be better againts sated devourer. People just dont realize that now
General Esdeath 18 votesIt suppose to be better againts sated devourer. People just dont realize that now
Except it's a core item tanks love to get for adc champs.
xxxMadLionxxx2 votesExcept it's a core item tanks love to get for adc champs.
So you prefer having no measures against sated devourer? Riot did add that -10 crit damage to 1 of those tank items. I think that was to help with thornmail losing some of its power on autoattacks
TurquoiseYoshi21 votesThat item (Randuin's Omen) also lost 100 HP and 10 armor on the same patch.
Jefftiffy1 votesThat item (Randuin's Omen) also lost 100 HP and 10 armor on the same patch.
Randuins Omen is actually better now against the people it was buffed against. You lose 100 health and 10 armor but gain 10% dmg reduction to crits. Basically at IE you go 250->225%. Against a 300 damage ADC that is about 750 dmg per AA crit or 187.5 damage less on crits. Meaning after 2 crits randuins is already stronger than it used to be a by far. Math OP.
Hrmm I wonder why Vayne is a problem now, oh wait she's the only ADC that doesn't rely on crits for most of her damage.
TurquoiseYoshi1 votesBut then for the times when the ADC doesn't crit (which is about half of the time), it makes you take more damage. You also can take less damage before you pop. Lastly, against everyone who doesn't crit a ton, like Zed, or Varus, or most AD top laners/junglers, you generally get less power.
Applying math to the situation in question OP.
It used to be good into most AD champions, but now it's just a crit blocker.
Jefftiffy1 votesBut then for the times when the ADC doesn't crit (which is about half of the time), it makes you take more damage. You also can take less damage before you pop. Lastly, against everyone who doesn't crit a ton, like Zed, or Varus, or most AD top laners/junglers, you generally get less power.
Applying math to the situation in question OP.
It used to be good into most AD champions, but now it's just a crit blocker.
You lose 10 armor which is maybe a 5% damage reduction at max. Doesn't really drop your defence too hard against non crits. Randuins I believe is also blocking damage on magic crits as well for some reason, so it isn't as bad as everyone makes it out to be. And contrary to popular belief, the counter to burst damage is HP and armor mixed with a bigger emphasis on hp. Armor helps drop it lower while hp stacked with it exponentially increases your chances of living.
TurquoiseYoshi1 votesRanduin's blocking magic crits is about as useful as Zhonia's Hourglass against a full AP mage team. Unless magic crits and AD crits are on a team, that 2700 gold could be spent in a better way.
YumaS2Astral1 votesRanduin's blocking magic crits is about as useful as Zhonia's Hourglass against a full AP mage team. Unless magic crits and AD crits are on a team, that 2700 gold could be spent in a better way.
To be honest you never buy Zhonya's for the armor. You buy it for the active effect, and only for it. Otherwise there are way better AP items, and armor items.
Also, Zhonya is pretty useful against many AP champions, for example: 
All of them have their ult countered by Zhonya due to those ult's delays and/or due to their ults losing their effects if the target become untargetable.
TurquoiseYoshi1 votesI know, my example was bad. How about building Scimitar against a team of Yasuo, Gragas, Nautilus, Mao'Kai, and Vayne?
YumaS2Astral1 votesI know, my example was bad. How about building Scimitar against a team of Yasuo, Gragas, Nautilus, Mao'Kai, and Vayne?
Scimitar is actually useful against Gragas' stun, Nautilus' root/slow, Maokai's snare, and Vayne's stun.
TurquoiseYoshi1 votesOkay, what about building Zeke's as a manaless AD champ?
YumaS2Astral1 votesOkay, what about building Zeke's as a manaless AD champ?
Champion Skin1 votesIf you want to counter Sated Devourer why wouldn't you build Randuins or Frozen heart as they reduce attack speed which makes the on-hit damage proc less and the "double hit" will also proc less
LordGeovanni1 votesthat really only changes a 1.5 second death to a 2.5 second death if the person doesnt have lots oc cc and mobility
Champion Skin1 votesWell if you go from living 1.5 seconds to 2.5 seconds you almost doubled the time you could tank the enemy And if you are building tank items you usually have lots of CC and you also usually have some damage dealers on your team to do the damage for you
LordGeovanni2 votes1-3 seconds is hardly tanking. rather that is being popped. and having lots of cc on a tank is irrelevant when carries also have lots of cc and they get get the added benefit of damage and sustain and mobility. not to mention the initial benefit of being ranged in the first place. and tanks defense compared to carries attack is usually 1/5 ratio
3TWarrior33 voteshow does it counter sated devourer? it doesn' t proc it twice and most on hit items will heal for all the damage that it does
Lugg18 votesIt doesn't do anything against sated. It only reflects PHYSICAL damage. So it doesn't matter if they have sated or not.
Hotlin3 Fling2 votesThe that's why they gave it armor scaling damage, so that it still does damage to on hit champs, minions and monsters
Lugg16 votesThe damage Thornmail does right now is countered with 
it's so bad.
The Yetii Rider12 votesThe that's why they gave it armor scaling damage, so that it still does damage to on hit champs, minions and monsters
Yes, but in order for that to scale you need to build armor instead of the MR that would actually reduce the on hit damage of sated.
Hotlin3 Fling12 votesIn that case they should make scale with both resists, not just armor
Taigongwang3 votesSimplest solution to making Thornmail good again: BLADEMAIL. Make the damage reflect component an active instead of a passive, with a noticeable effect so that those ADC's know they cant attack that target without killing themselves.
Blademail works in DoTA because while it is EXTREMELY powerful, it is also very obvious as to when it gets used. So it can pass with a 100% damage reflect as True damage.
But Riot probably just wants to nerf tanks and anything that slows down ADC's and assassins at this point. Honestly just feels like it from their recent balancing.
ComannderShepard2 votesyou'll probably get more countering from tabi and randuins with the -10% physical and crit damage. As a avid tank top/jungle/support player RIP
Nearance2 votesI have never bought after its nerf. Not worth anymore. 
Randomonium2 votesI like the idea of giving thornmail an active, though I'd like to see something more unique than just doubling the passive. Maybe make the active increase the passive an amount proportional to how close you are to the champion attacking you. Like if you were in melee range the passive would be doubled but at 800 range the active wouldn't provide any extra effect. This would give some strategy and also give the ADCs some counterplay (rewarding good kiting.) This active would also make thornmail even better at countering melee devourer junglers.
SoMNia2 votesBut "the same result as previous version" was horribly broken and should never have been a thing, so...good. That was the point. They didn't WANT it working the same way as the previous version. The ADC should not be killing themselves from Thornmail damage alone just by attacking a tank.
Wajster2 votesIdk what they were thinking with the nerf. The item is useless right now.
Jingerbeardman1 votesDunno what world you are living in... i use it and it is even more effective now than it was before, at least it is in the early game. It does fall off a bit in the late game but I believe that was the entire reason they tweaked it. It was being picked up to often by anyone in an effort to thwart the enemy adc or other champ that was countered by the item. Now it is an item that works best only on the champions it is intended for, tanks.
Riv x Kobe3 votesDunno what world you are living in... i use it and it is even more effective now than it was before, at least it is in the early game. It does fall off a bit in the late game but I believe that was the entire reason they tweaked it. It was being picked up to often by anyone in an effort to thwart the enemy adc or other champ that was countered by the item. Now it is an item that works best only on the champions it is intended for, tanks.
Do you know how to do math at all? Its only a little bit better early game, but much worse late game. Not only that but many of the other Armor items are better pick ups early game because they also give you health and better passives/actives.
It not only costs more (effectively reducing how good the item is in slot) but it also only reflects 15% of damage instead of 30%. Oh but that bonus 25% damage from armor is so good. Right?
There is literally no way that you can seriously say that it is more effective than it was before when it is statistically worse, and has a higher cost, meaning it cannot logically be more effective than it was before.
Jingerbeardman2 voteswell, as someone who plays rammus top I have noticed a considerable increase in my reflect power out of ball curl early game thanks to that bonus ratio. It actually is very powerful early on and into the mid game, I find that ADC in the early mid game actually end up killing themselves even faster than they did before this change. BUT like I stated in my original reply it is not as effective late game which is what they intended. They didnt want thornmail to be some catch all screw you ADC especially alongside all of the new juggernaught items. Thornmail is meant to be more of a niche pick against high attack speed auto champions and not some catch all stop an ADC item.
Oh and since you are clearly hung up on math it is 100% possible for thornmail to deal more damage than in the past, just not in the late game. it does considerably more damage in the early game compared to its previous iteration.
Don't forget this little guy ;)
Why does everyone keep forgeting about him?