The Reason ADCs Are Required
Yeah, they're strong this season, but ADCs have always been a required component of an composition. Why? A few reasons:
- Turrets: The only champions that can kill turrets quickly and safely are ADCs. Other champions might kill them faster in split pushes, but very few non-ADC champions can kill turrets in a siege-like scenario.
- Ranged DPS: There are very few picks that deal consistent magic damage like ADCs can. Azir, Cassiopeia, Heimer, Karthus, Kayle, Orianna, Zyra - a lot of those are a stretch, others are badly gated by mana, and most need a lot of items.
- A lot of supports are designed with ADCs in mind. Janna's E grants AD, Nami's E is on AA, Lulu's E is on AA, etc.
Put all of those problems together and I think that's why ADCs are so required.
- Riot should release more ranged APCs with relatively reliable DPS and more supports that synergize with AP champions in lane.
- The current damage formula for turrets is "base attack damage plus the higher of bonus attack damage or 50% of ability power." Late game damage per hit between a 600 AP APC and a 300 AD ADC will be close, but ADCs also benefit multiplicatively from AS. The above formula should compensate for AP champions' lack of attack speed.

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