User blog comment:ClariS/AD has Diminishing Returns!!/@comment-174.1.215.227-20120829194437

this post is pretty silly. i will give you the equation for damage output for auto attacks without additional effects:

AA damage output = ad*atspd*(1+crit%)*(1+bonus critdmg)*(1-dmgreduction)

which implies, you will see the maximum AA damage output if you maximize the % of each multipliers. it takes a bit of effort to explain this in detail, but in short focusing on one stat will of course have diminishing returns. that is why people build ie,pd,lw on ad carries and having a balanced autoattack stats and not 3 bts because it is too inefficient with 300 ad diminishing return. that also means, however, that other stats will create same effect, such as crit percent or aspd.

for ap, damage calculation is bit different because there are too many factors to consider. it is fairly easy, though, to do an individual skill damage calculation

individual ap skill damage output: (flat dmg+ap*apratio)*cooldown*(1-dmgreduction)

it is similar with autoattacks, in that focusing on just one stat will tend to have diminishing returns. however it is interesting to note that cooldown will have incremental effeciency (when seen exclusively) as you stack the stat by the nature of the stat