AP items are proposed for a massive overhaul soon on the PBE. On this post you can read Riot Xypherous’ statement about it http://boards.pbe.leagueoflegends.com/en/c/champions-gameplay-feedback/q2694bqE-513-core-ap-items-pass but what would this mean for the meta and how would it affect individual champions?

The main idea behind the overhaul is to add diversity to AP builds by making Needlessly Large Rod items have not quite as much AP anymore. The core build of just about every AP carry is a mana item, Void Staff, and Large Rod items, thus by moving AP from Large Rod items to the mid-tier AP items Riot wishes to open up more item diversity. The Large Rod itself is also now proposed to cost 1250G and only give 60AP. This alone will make mid less snowbally as a Large Rod buy won’t be as strong a back if your opponent can’t afford it as well as making Large Rod items far more acquirable for junglers like Fiddlesticks and AP Evelynn as well as for supports like Morgana due to not needing 1600G in one back.

The only 120 AP item will now be Rabadon’s Deathcap which will cost 200G more but now will give 5% more AP. The point of this change is to allow there to be an item purely for AP stacking whereas other items will have less AP but also provide differing utility. Adding more to the multiplier, however, will benefit champions who get free AP from other sources like Cassiopeia as it will stack multiplicatively with her passive. The change also benefits utility mages who gain more power from flat AP than most through shields and the like without caring as much about stats like Magic Penetration for example Orianna and Lulu.

The other 120AP items, Zhonya’s Hourglass and Luden’s Echo, will now only give 100 AP. In compensation, Zhonya’s will cost 3000G. This again will help AP junglers and support Morgana that often feature Zhonya's as core in their builds. Luden’s will also cost 3000G but will give a significant 10% movement speed instead of 7%. This could be looked at as significant from 2 directions as it gives more mobility to poking siege engines like AP Kog’Maw who lacks ways of avoiding threats and thus could use the movement speed as self-peel. The other direction is that it would help champions like Katarina and Annie be roaming machines with Luden’s rush from midlane. Champions like Lulu will however suffer from this change as they relied on Luden's as another damage scaling. This change to Luden's would likely make Lulu either only build it later in her build or more likely just always go for the Deathcap as her second item and play as a super support. She possibly might also go back to using Lich Bane as her secondary damage scaling instead of Luden's.

So immediately the thought should be that Deathcap plus another Large Rod item will now give less AP for almost the same amount of gold, does this mean that AP champions won’t be as strong lategame? Well Void Staff will now give 80AP to make up for some of that. However, it will cost over 200G more and actually make the item less viable as a second item due to being less gold-efficient as a standalone AP item making Void Staff second item less viable.

Other AP items are also getting scaled up. Items like Seraph’s are getting an extra 20 AP (Cassiopeia buff again anyone?). Rylai’s will cost 100G more but gets a slightly more effective slow (Cassiopeia...). WOTA is also effectively getting 5% less Spell Vamp but that Vamp specifically will be calculated before resistances which WOTA Cassiopeia players like Vici Gaming’s HeTong from the LPL will very much appreciate. Vladimir also will be favoured by the WOTA buff and the improved sustain against tanks in particular should be well noted.

Rod of Ages is also getting significantly changed towards being far more of a mage item than a fed Maokai item. The health on the item will be cut by 150 in exchange for increased AP and mana. I see this as making Righteous Glory definitively the best Maokai item as well as being an improvement for Ryze and Kassadin builds and possibly even being a decent option on lower range mages that don't depend on the 20% CDR of Athene's/Morellonomicon.

Azir might also possibly be able to actually buy Nashor’s Tooth now with it being changed to give 20 more AP (though losing 10% attack speed). It would take some calculation to work out if it actually was viable with the change but it’s an interesting prospect. This is also definitely a Kayle buff who already gets close to capping in attack speed with both Nashor’s and Runaan’s Hurricane and could make much better use out of the increased AP.

Liandry’s Torment is looking at getting an extremely significant bonus 30 AP for only 100G more in cost. This is huge and would make the item far more viable on mages looking for a little more burn in their spell rotations. Mages that turned their nose up at Liandry’s due to its low AP value might be a little easier to sway with this change. On top of this the build path would become far easier with Liandry’s now building out of Haunting Guise and Blasting Wand. Also yes, this is a Teemo buff.

The final items to be changed are the 20% CDR mana items that are simply getting to buy another Amplifying Tome in their recipes in order to be an alternative buy of Fiendish Codex plus Amp Tome around the 1200 gold mark to compete with the new Needlessly Large Rod price. This is a relatively minor change as the laner could pick up a Doran’s Ring plus Codex instead on that back but nonetheless is relatively nice for giving the player options.

Overall I believe these changes would make Cassiopeia outright the best midlaner in the game if they made it to live today but if numbers were worked out around her kit then the net result would be an increased diversity in AP items which should be very much welcomed as giving the player more options to respond to different scenarios makes the game far healthier.