Crit Rate
ok last i've heard its 5luck =1% or 1luck=0.2%
i've also seen after 50% it becomes 4luck=1% or 1luck =0.25%
from what i hear atleast teh 5luck=1% is still the standard?

Crit Damage
as for crit damage
this is a pretty old post
this says round 200 luck your crit damage is 200%
and around 600 luck your crit damage is 300%
and i cant tell when it was last edited.
i thought i saw a formula somewhere but i dont recall and cant seem to find it now.


just want to see whats more precise 

http://www.top1gaming.com/content-71137-Luck_damage,_my_theories.html
very usefull post now quoted below