Is it permissible to say "good luck" or "bad luck"?

"Luck" is one's share of good, and it may also refer to one's share of good or evil in general. People's saying "good luck" or "happy luck" as a supplication and wish for good is not forbidden; rather, it is praiseworthy. It is not permissible to supplicate with evil against a Muslim.

If "good luck" or "bad luck" is said as a statement of fact, there is no harm in it, whether it is a statement about a blessing that necessitates gratitude or about adversity, provided that it does not involve discontent with Allah's decree, or ill-suspicion of Him, or attributing evil to Him.

As for whoever believes that "good luck" or "bad luck" results from causes unrelated to Allah's decree, such as linking it to stars or numbers, their saying is prohibited and forbidden.

It is preferable to avoid the phrase "bad luck," because a believer tends to have good expectations of Allah, for what befalls them may contain all good, as Allah Almighty said: (And it may be that you dislike a thing while it is good for you).