I have two classes that are basically "thief" skillsets. There's "Steal" which is where you can unlock chests and doors without a key. Opening the chests typically loots a single medium to semi-rare item from the chest. A variable that tracks the LUK stat for this character plugs the stat into a formula that determines "success" or "failure" or even "which loot do you get?". My second skill is called "Pillage", which works like Steal, except it determines how many low to medium items you get from a chest as well as if you rolled high enough for the "super-rare" loot in the chest. Failure on any of these tables "destroys" the loot.
Likewise, I've also coded a few events that only show up when LUK is at or above certain thresh holds. The way a few of my Quests unfold is also somewhat determined by the LUK stat (keep in mind, these Quests aren't completed with luck and you aren't given the best outcomes with luck... it's just that luck can sometimes nullify some of your mistakes and play out the events a little differently).
I imagine you could do other things with it as well, like if you have some kind of gambling in your game, you could factor in the stat. You could also factor in chest drops just from that stat alone. You could even have it factor into whether or not a field skill succeeds (like jumping a cliff edge or something).
There's a lot of things you can do with LUK, but there aren't many people who consider those options, and I have no idea why. I rather enjoy using it
