Formal:
* Powodzenia! (pronounced poh-vod-ZEH-nya) - This is the most common and general way to say "good luck" in Polish. It's suitable for almost any situation.
Informal:
* Szczęścia! (pronounced SHCHEN-shcha) - This is a more informal and slightly less common way to say "good luck." It's best used with friends or family.
* Trzymam kciuki! (pronounced TRZY-mam KCHOO-kee) - This literally translates to "I'm holding thumbs!" and is a playful way to wish someone good luck.
Specific situations:
* Do egzaminu! (pronounced doh eh-gza-mee-noo) - This means "for the exam" and is a specific way to wish someone good luck on a test.
* Na szczęście! (pronounced nah SHCHEN-shche) - This means "to good luck" and is a way to wish someone good luck on a specific endeavor.
You can choose the best phrase depending on the situation and your relationship with the person.