Fred's lucky dice are usually used to make a decision, especially during difficult times.
He had it since he was an infant because it was his first toy gift given from his father and it has become a part of him that he shouldn't lose. He's very sensitive about losing them and practically helpless without them.
In Episode 41, he lost his lucky dice and can't decide without it. A kid picked it up and fortunately, he encountered the child and ask to give it back to him but refused. So the only way to get it back is by scaring off of him. As Fred returned from his successful search, another problem emerged aliens came to play a game of gamble. If they lose, the whole earth will be detonated by a bomb and if they win, the bomb shall be halted. However it was more difficult than they imagined, the aliens are cheating so Fred used Friday (instead of his lucky dice) and fortunately they won.