Quote Originally Posted by Loaf View Post
Luck is like Evasion. Pretty much the same stat almost.
Luck's main purpose is to affect your critical rate. The higher your luck, the higher your critical rate. At the same time, luck effects your chances of hitting an enemy, or an enemy hitting you.

Luck is a stat for assholes and completionists. Leveling your strength/magic is the easier way to ensure that you'll hit for 99,999 each time, and leveling your evasion/accuracy is the easier way to ensure that you'll hit your target every time, while making sure you don't get hit.