Chibz said:
Luck is only superstition.
Maybe in real life, but that is for another time for another discussion.
Luck works effectively in game. If you're nice to your neighbors, nice things will happen to you in your game. If you have 'lucky' items in your house, then you'll increase your chances of good things happening to you. There a lot of things that can happen if you have very good luck, some things that the more veterans (of AC) can explain to you as I do not know much information beyond what I've already told you.