Any tips on getting the "I Love You Son" achievement?

[Lin Bug]

I've gotten somewhat far in killing the rouletters, but I keep getting stuck (already past the initial three rounds). I've leveled up a guy with high luck, but it doesn't seem to be enough. Anything seem to help?

[Shuno]

There's nothing to help. Sheer luck.

Although I didn't bother to complete that until I hired all the guys. Then luck didn't even matter, I had too many of them.

[Mr. Purr]

Two words: "Save scumming" Make a save file and keep loading it until you get the desired results. And save after every rouletter you kill.

[Ajogamer]

The luck stat makes no difference at all, so don't bother worrying about that; just use anyone you consider expendable. If you only care about the achievement and not actually keeping the rewards though, then it becomes pretty easy once you get accumulate more party members, since you can afford more deaths, then just reload once you got the achievement.