Talk:Elixir of Iron/@comment-4068613-20141122115001/@comment-26231232-20150721165802

Yeah, tenacity stacks multiplicatively, not additively, otherwise it'd be ridiculous. From what I've seen, it goes like this:

35% tenacity from Merc Treads means CC only affects you for 65% of the duration. 25% from EoI means CC only affects you for 75% of the duration. 10% from Tenacious means CC only affects you for 90% of the duration. 10% from Mundo's W means CC only affects you for 90% of the duration.

.65 * .75 * .90 * .90 = .394875

So, under those conditions, you're only affected by ~40% of CC duration, or, in other words, you have ~60% Tenacity. This is done to prevent Tenacity Shenanigans like Garen, Irelia and Mundo reaching 80%+ or 90%+ Tenacity.