Formal:
* 玩得开心 (wán de kāi xīn): This is the most common and neutral way to say "have fun." It literally translates to "play happily."
* 祝你玩得开心 (zhù nǐ wán de kāi xīn): This is a more formal way to wish someone fun, meaning "I wish you have fun."
Informal:
* 玩得开心点 (wán de kāi xīn diǎn): This is a more casual way to say "have fun" and is more suitable for friends or close acquaintances. It literally means "play happily a little bit."
* 玩得高兴 (wán de gāo xìng): This is another informal way to say "have fun" that means "play joyfully."
* 玩得尽兴 (wán de jìn xìng): This means "play to your heart's content" or "have a great time."
You can also use the following expressions depending on the situation:
* 好好玩 (hǎo hǎo wán): This means "have fun" in a more general sense, like "have a good time."
* 放松一下 (fàng sōng yī xià): This means "relax" and can be used to encourage someone to have a good time.
* 尽情享受 (jìn qíng xiǎng shòu): This means "enjoy yourself" and can be used in situations where you want someone to really let loose and have fun.
The best way to choose the right phrase is to consider your relationship with the person and the context of the situation.