Black King Bar

The Black King Bar is an Item purchasable at the Main Shop, under Armor.

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Gives Magic Immunity. Duration and cooldown decrease with each use. Duration starts at 10 seconds and decreases by 1 each use. Cooldown starts from 80 seconds and decreases by 5 each use. Duration and cooldown will bottom out at 5/55.

Ultimates and skills that BKB does not affect are from the following heroes:

Bane, Beastmaster, Batrider, Pudge, Silencer, Clockwerk, Faceless Void, Enigma, Vengeful Spirit, Necrolyte, Anti-Mage, Lich, Juggernaut (Will still damage, as it deals physical damage.), Sniper's Assassinate.

The only non-ultimate I can recall that disables through a BKB is Axe's Call and the new Abyssal Blade item.