2 Steps Solution to AD itemization dilemma
I am going to put the TL;DR at the start of the thread so everyone can see, and then going with the expanded explanation below ** Step 1**
Rework Lethality in a new stat, called for simplicity Lethality 2.0 Tie Lethality 2.0 to %maximum health damage , namely for every X amount of Lethality 2.0 you have, you get an Y amount of %maximum health damage Make ARMOR mitigate the % maximum health damage given through Lethality 2.0 items (aka, if though items the Letality 2.0 stat gives you 1% max hp damage, and your enemy has 100 armor, the amount of % max hp damage dealth through Letality is 0.5%)
Reduce across the board the amount of any kind of % health damage existing in the base kits of any champion that has it and could exploit the new Lethality 2.0 stat
Step 2 (Once you got the framework of Step 1 fown and have collected the data on how much damage the Lethality 2.0 itemization bring to the table)
Reduce the amount of bonus damage dealt by a critical strike - the amount of the adjustement depending on how much damage the Lethality 2.0 builds are providing -
Extended reasoning - WARNING! wall of text -
There has been for AGES in League a problem in differentiating the AD itemization for the different kind of AD damage dealers in the game. The root of the problem is clear, AD itemization enhance basic attacks so that the most popular and used AD items have generally being swing between either "ball of stats" items or crit oriented items, and this has become a nightmare to balance, since its effect heavily influence the interactions with armor and health stats, and the way those latter stats interact with each other Basically, AD itemization and thus meta champions tend to focus towards the optimization to the question "which combination of champions/items have the highest current raw damage?". To avoid this situation, Riot started to popularize the introduction of %hp damage ( either max, current, bonus) in the design of recent champion kits, as it was the solution to create new way to create damage different from the ball of stats syndrome - often gated by the infamous "3-hit passive" thing -, but this clearly created other problems as made unviable health stat unaccompanied by resistences
The attempt Riot tried to do with current Lethaliy to boost a different kind of AD itemization for some champs that didn't have a proper itemization backfired in a spectacular manner, as Lethality became as much hard to balance as the rest of AD itemization, if not more for the current edge cases when it was too strong/weak or champions outliers that exploit the way lethality works
The reason why these problems exist and Lethality attempt failed, is because Riot hasn't fundamentally being able to properly divide proper burst damage by sustained damage in AD itemization. Critical strikes work as BOTH burst (because of the additional bonus damage) and sustained (because except some cases it is generally enhanced by some kind of attack speed stats in the builds), while the champs that can't build for crit have gone to the most optimal "ball of stats" itemization, building different things depending on what had the highest raw power at the moment BUT Critical strikes can't just be deleted from the game BECAUSE they represent the only kind of RNG solution actually available to keep the game fresh and avoid the phenomenon you would have in certain games where the damage calculation would become too precise to make the game stale as an optimal combination of what actually deals the optimal amount of damage would be found and the meta solved thus making the game mainly a question of pure mechanic skills (see Starcraft)
With this premise, how to solve the problem? Completely overturning Riot philosophy about item balancing. Riot has always refused to put % max health damage in items because it was deemed as too risky to make this kind of damage accessible to anyone...except that right now the amount of champs with % hp damage is so relevant that it becomes a moot point to keep this stance when you can have literaly more than half of champions in a game played according with meta with % hp damage Lethality experiment has failed because it was basically a reskinned flat armor pen stat which do not solve the root cause of the issue
You got to focus about what is the target of the different kind of AD damage you want to have in the game, and that's where this proposed change hit the spot % max hp damage is clearly meant/thought to be a stat against tank that stacks health, so what they should do is really to should push stronger on the nature of the stats, and in the meantime like push crit into definite burst territory, as basically the combination with attack speed allow marksmen which were supposed to deal sustained damage as class to actually blow out pretty fast any kind of enemy in fights that doesn' end in them being bursted in less than 1 second By narrowing down this focus, you also make clearer which defensive stats should be useful against certain kind of damage. Armor would become the defensive stat to go to fightLethality 2.0 builds that would be focused towards the enemy comps with quite a lot of tankiness in form of hp items; at the same time Health would become more important against crit aka burst, since health would last longer vs this kind of damage than before (more crit hits are needed to shred thorugh the same amount of health now) This would also help to solve the problem of "generalist" defensive items (aka armor + health items) that are currently ruling defense itemization, as champions that want to build tanks have to make more impactful decisions about which defensive stat to prioritize against the champs that are doing the best in the enemy team and their expected offensive itemization, making generalist items a bit less useful as they would be less efficient to counter a specific kind of damage
