History over the past 2 years tells us ADCs are always unhealthy when: 1) Crit builds are too cheap and 2) ADC items are too expensive. It also tells us tank items are way too cheap and the argument that "tanks get less gold thus need cheaper items" no longer holds up, especially the early game. The past year also tells us supports being too strong makes ADC too strong and makes assassins and bruisers fucking garbage.
Solution is simple. If Crit is too broken when not too costly in it's current state, then nerf the power of Crit to justify lower costs. This also means tanks will have to hits, but also changes because their current item set is clearly what it should not be. Support items also take a hit, specifically Ardent Censer and tank ones which tanks are abusing.
* Infinity Edge's critical damage modifier reduced to +35% from +50% (235% AD for crits from 250% AD). Attack damage lowered to 65 from 70. Cost reduced by 50 gold.
* Reduces overall late game power with reduction to AD and Critical Damage, but slightly compensates with a cost reduction. Cost reduction is also to keep decent combine cost with a future change/
* Essence Reaver reworked. 2900 Gold = Caulfield's Warhammer + Pickaxe + Cloak of Agility + 125 Gold. 60 AD, 20% Crit Chance, 20% cooldown reduction, same passive.
* Cooldown reduction is given right away and cost is heavily reduced, making the item a much stronger first item. However, the lost to 10 AD and 10% cooldown reduction makes it much worse later into the game, where caster style ADCs should fall off but mostly do not currently due to overall ADC strength and scaling being too much.
* Rapid Firecannon's passive and Stattik Shiv's passive can no longer co-exist, similar to the Harmony and Dissonance passives of Mikael's Crucible and Athene's Unholy Grail respectively. If possible, make buying one disable the buying of the other.
* Lord Dom's bonus damage based on health difference reduced to 10%. Bonus armor pen increased by 5%. (Power shift from killing bruisers and tanks to killing tanks moreso.)
* Rageblade get's slightly changed. Stacks of item now give 6% attack speed from 8%, but the item now has 30% attack speed starting (11% attack speed loss). Cost is also reduced by 200 gold.
* This is mainly to lower Kog'Maw's power much like Infinity Edge, but cost reductions to keep neutral.
* Bami's Cinder is the core item for tanks, or is supposed to be but it sucks. Build path and cost changed to Ruby Crystal + Ruby Crystal + Rejuvenation Bead + 300 gold; total cost of 1250 gold; 50% base health regen + 350 health. Passive damage adjusted so it hurts champions a bit more and hurts minions about the same.
* Basically this makes Bami's Cinder a strong laning phase item mirroring Tiamat. Don't worry, other tank items are being nerfed to compensate for Sunfire being made into a good item. Build paths for Cinderhulk and Sunfire changed accordingly to Bami's Cinder + Chain Vest/Smite Enhancement.
* Following the Bami's Cinder change, Sunfire gets it's own set of adjustments. Cost reduced to 2850 gold, gains +100% base health regen following Cinder's change. (800 Gold combine cost.)
* Stoneplate nerfed and changed. Builds from 2 Aegis of Legions. Gives 60 Armor and 60 Magic Resistance plus 20 Armor and MR while near 3 or more enemies. Costs 3300 Gold. Active nerfed so health counts as base health instead of bonus (no longer interacts with Locket or Cho'Gath's ultimate).
* This item is currently overpowered and if you showed this item in it's current state to someone in season 2-5 people would ask if you were insane. Also tanks have no expensive, late game item so I thought they should have one instead of having nothing.
* Locket HP scaling reduced to 15% bonus health. Stop building it in top lane and jungle.
* Knight's Vow armor reduced by 5. Damage mitigation/healing based on bonded ally lowered to 8%.
* Targon's Embrace, Face of the Mountain, and Eye of Equinox now give 1.5x gold to the player (who has the item) when they execute a minion. (Compensation to their items being nerfed.)
* Coin gold generation is nerfed. (LCS game a guy had 2000 gold more gold with coin than a guy with spellthief.)
* Ardent Censer attack speed reduced to 20%. Healing onhit reduced to 10-25 based on level.
* Maokai's healing from his passive nerfed. Health per R - Feast reduced on Cho'Gath. Sej and Zac CC is nerfed. Zac's latest nerf gets reverted though.
ADCs are less damaging. Tanks are less tanky. Supports are less overpowered. Tank supports (hopefully) stay viable. Cho'Gath can't locket for 1000 and can't nuke for 1700. ADCs heal less with lifesteal since their damage is reduced. Bruisers are more viable.