Lethality
How exactly do the lethality stats work? Do they stack? If they do, why are they unique passives instead of just stats on each item? Or do they only stack if the lethality values are different?
5 Comments
They give armor penetration based off of your champion level. They are unique so you may only purchase one of a particular item and still recieve the lethality. So you can't rune 5 
.
Unique passives that aren't named do stack as long as they come from different items, so two 
won't give you 20% cooldown reduction, but and 
will.
Named unique passives (like _ lifeline_ on 
and 
) work the same, but they will also apply both effects, however only the highest value of each of those effects will be used. For example, 
and 
both have the Spellblade unique passive. When the effect is used, it will apply the AoE slow from , but apply the damage from as it is the higher value of the two. You will not apply the damage from both spellblade procs.
It's essentially just to stop people from only buying whichever item is the most gold-efficient and preventing items being overbearing when stacked. Hope that helps.