Well I was looking at the stats and description of Infinity Edge and critical strike damage/ chance, and noticed something important.

Link: http://leagueoflegends.wikia.com/wiki/Infinity_Edge

Critical strike damage/ chance only counts with auto-attacks, NOT abilities (except for a few which are. Champions obviously deal the vast majority in their damage with their abilities, so how viable is Infinity Edge for champions such as Pantheon and most other AD? Who is this item most viable for?

I see this item being built frequently yet I feel that building a second Bloodthirster or something similar is a better, more cost efficient option (IE is 3800, BT is 3000). If there's something I don't understand about Infinity Edge, critical strike damage or chance, let me know.

should be built on most AD carries, but not anyone else.

Pantheon and AD carries are about it, and with black cleaver I don't think pantheon uses it anymore.

If you're using abilities to do the bulk of your damage, you're usually right (exception:Garen and Gangplank). However, if a bulk of your damage is autoattacks, like most AD carries, that's who you get it for.

Its a go-to for ad carries, and any ad increases auto attack damage, which takes down turrets, minions, and champions when cds are up. Abilities are not the only things that matter. Take Vayne, for example. She's an auto attack killing machine. Sivir too, with her run speed passive.

If you are AD Carry, you should generally always get IE sometime in your build. For most bruisers, they should usually get BT for damage because their spells (some of them) scale well with attack damage. You always get the exception, like IE on Garen instead of BT.

Only non-adc I see building IE is Gangplank. Maybe Pantheon too.

Ah, that makes sense - ADC's have that ranged/ speedy basic attack that works with IE.

Thanks

I like to go IE+SotD on my assassins from time to time. But usually very last in my build.

Any ability that can critically hit is affected by Infinity Edge's passive. That being said, if an ability can critically hit, it will explicitly state it in the ability description. Understanding those two things means that any champion who does not have a special interaction with critical hits, whether it be through constant use of basic attacks or a core ability that can and should critically hit a target, is a champion that should not build Infinity Edge.

This thread is covering the basic of the basics: abilities that don't crit won't crit. It's actually really very pointless.