1.
N-UNCOUNT
Luck or good luck is success or good things that happen to you, that do not come from your own abilities or efforts. 运气
例：
I knew I needed a bit of luck to win.
我知道我得靠点运气才能取胜。
例：
The Sri Lankans have been having no luck with the weather.
斯里兰卡人一直没运气碰上好天。
2.
N-UNCOUNT
Bad luck is lack of success or bad things that happen to you, that have not been caused by yourself or other people. 霉运
例：
I had a lot of bad luck during the first half of this season.
我在这一季节的前半季遭了很多霉运。
3.
CONVENTION
If you ask someone the question "Any luck?" or "No luck?," you want to know if they have been successful in something they were trying to do. 运气如何
[非正式]
例：
"Any luck?"—"No."
“运气如何？”— “不好。”
4.
CONVENTION
You can say "Bad luck" or "Hard luck" to someone when you want to express sympathy to them. 运气不好 (表同情)
[非正式]
例：
Bad luck, man, just bad luck.
运气不好，老弟，只是运气不好。
5.
CONVENTION
If you say "Good luck" or "Best of luck" to someone, you are telling them that you hope they will be successful in something they are trying to do. 祝你好运
[非正式]
例：
He kissed her on the cheek. "Best of luck!"
他吻了一下她的面颊：“祝你好运！”
6.
PHRASE
You can say someone is in luck when they are in a situation where they can have what they want or need. 交好运
例：
You're in luck. The doctor's still in.
你运气不错，医生还在。
7.
PHRASE
If you say that someone is out of luck, you mean that they cannot have something which they can normally have. 运气不佳
例：
"What do you want, Roy? If it's money, you're out of luck."
“你想要什么，罗伊？如果是钱，你的运气不怎么样。”