Makes no sense to me. Thornmail's passive returns 30 percent of the basic attack's damage in magic damage. So let's say the enemy ADC is 5/0/1 or something. I decide to buy Thornmail and a Frozen Heart, (wouldn't really do this but theorycrafting), so I have 200 armor from items. Meaning probably around 260 armor. So I want thornmail to actually do something, so they're dealing no damage to me, hence no damage in return. Probably 10 magic damage coming back. Most useless item to me.
Talamare4 votesNo
It deals a % of the unreduced damage back to them as magic damage which is then reduced by their magic resist
Lord Dusteon3 votesIt returns 30% before reduction, not after.
HITMANNOJI1 votesOh thanks for the reply. pretty fast. I thought it was something like that i saw it on an older forum in forum's but its kinda weird to me, because sometimes im a retard.
Fadedpf1 votesThornmail is garbage. It does nothing if they are fed. Randuins and HP will help you survive
Talamare2 votesThornmail is garbage. It does nothing if they are fed. Randuins and HP will help you survive
It does even more if they are fed...
Its fine if you die, if thornmail took out half their hp in the process
It sucks if they stacked Lifesteal tho, but at least then they might not use your face for free heals
Thornmail is definitely in a good spot
Celestial Lion121 votesthornmail useless? I was dueling a 
earlier as 
I kited really well and took little damage from him at all but i still lost because thornmail did 68 percent of my health and the other 32 was from his ult.
Critkeeper1 votesthornmail is op