For every 10 base luck you get 1 perfect dodge. It is not reduced by mobs, and caps at 100, rather than 95, but so many skills in the game negate perfect dodge or crit dodge as a lot of people call it, and autohit. In pvp, a perfect dodge build is pointless. In pvm it's perfect. Especially if you're just tanking or still have the ability to kill easily.
Two fortune swords on a sinx are easy times.