0 - infinity Luc = 1.5x attack
It multiplies only your attack value, which is also affected by elements and your opponent's defense. However, Luc also adds random damage, which can be anything from 0 to 1.5x your Luc. If you have 500 Luc, it will add 0 - 750 damage.
(1.5 * (att*ele - def) + 1.5*(number between 0 and Luc)) - absorb
This applies to all amounts of Luc