YOu're in luck.

You're lucky.


Do both of the above convey a similar idea? Thanks.
I agree with opti, although there are exceptions. I knew an auto mechanic a few years ago who would always preface the bad news with, "You're lucky!" (He'd then go on to tell me how much worse - and more expensive - it could have been.)

I think "lucky" is often used this way (in a negative sense) for "momentary" luck. "You're lucky the gun wasn't loaded." "You're lucky you weren't driving fast when the axle broke." In these cases, "You're in luck" doesn't seem to fit so well.

- A.
I want to emphasize Opti's comment about "in luck" meaning at the moment. You would say that only in reponse to a recently expressed need or desire.

I was hoping to have a chance to talk to you about the Acme project. // You're in luck - my 3 o'clock meeting just got cancelled.

My tooth really hurts. Can I get in to see the dentist today? // You're in luck - we have an opening at 10 a.m.

I was just thinking about how much I miss you. Do you think we'll be able to see each other soon? // We're both in luck! I have a conference in your city in two weeks!
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For me, yes
However, to be lucky can imply that the luck has lasted over a period of time.
To be in luck applies to the moment.
You're lucky - meaning generally
You're in luck, (because) we have them in stock - meaning you are lucky NOW
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"You're lucky the cops didn't pick you up for drunk driving." It just occured to me that this might be considered an idiom. Perhaps someone can verify. It's really a special case. The "lucky" part is present tense, but the momentary luck applies to a (recent) past incident. In GG's "You're in luck" examples, the momentary incident is very much present tense.

It may also be expressed as "You were lucky," especially if the incident was in the more remote past. "You were lucky your father had a job during the great depression." OR You could be lucky now about a past event. "You're lucky your parents could afford to send you to college."

At any rate, these all apply to specific incidents, rather than a general trend.

- A.
Avangi"You're lucky the cops didn't pick you up for drunk driving."
I read this as being in the present tense because you are STILL lucky that the cops didn't pick you up for ........................
I agree 'were lucky' is possible, but I think then the luck applies to that time when the cops didn't pick you up.