This is not true. Armour *reduction* can take you below 0 armour (or magic resist), but penetration will reduce to a minimum of 0. Furthermore, only flat reduction can do so (since % reduction by definition can't go negative).

There are still a few sources of flat reduction in the game. Nasus spirit fire, Corki gatling gun, Taric shatter, etc. However, unless the enemy team is intentionally stacked to take advantage of this, you'll pretty much never be dropped below 0 anymore now that Black Cleaver doesn't have flat reduction.

(And if they do have a funny team which can give you -75 reduction or so, then just buy a single chain vest and you're safe).

yes, i stand corrected. i don't think any items in the game give reduction anymore (if ever) and i dont think any abilities do either? where i got tripped up. thanks.

Nope, with the Black Cleaver change 0 items exist that can give flat armor reduction. The only way to get flat armor reduction is from champions now.

That's Nasus, Corki, Kog'Maw, Taric, and Rammus.

Incidentally, on the other side of the boat, flat MR reduction is relatively common. It's unusual but far from impossible to have your MR dropped below 0 for uber magic damage.

Not only that, but flat reduction for both armor and MR apply first in all calculations. If you had 100 armor which got reduced by 5, Black Cleaver would reduce the remaining 95 and then penetrations would do the rest normally.

So unless someone went crazy afk on SR at level 1 and returned to a game of level 18's with armor reductions, you will only very rarely see negative armor.

Fun fact: Flat MR reduction used to work with Galio's passive, potentially causing him to have negative AP. Sion also used to be able to obtain negative AP with a bug on Guinsoo's Rageblade. Both bugs have been fixed.

Fun fact part 2: If Attack Speed ever drops below 0.000, it rolls over to 2.500 (can't happen in legitimate play though).

Well, my team was just destroyed by a Garen.

He didn't have a single Black Cleaver.

Granted, we were all squishy melee and all he had to do was spin to win... but it still surprised me. I had two cleavers, and could barely scratch him. Frozen Mallet + Sunfire Cape and his silly little damage reduction shield. Interesting.

Well there's your problem.

Pretty much... except Ezreal... but he rushed Runaan's.

Too bad it costs an arm and a leg to get all these cleavers.

True. Luckily, it's usually the enemy arms and legs.