Help! I accepted a job - can I change my mind?

(Fortune) -- Dear Annie: When I finished my MBA this past spring, I got three pretty good job offers. But the employer I really wanted to work for kept putting me off - scheduling more rounds of interviews, telling me they still had other candidates to see before they could make a decision, and so on.

I took all this stalling to mean they probably would not make me an offer, so I took a job with another company. Well, wouldn't you know it? Two weeks into my new job, my first-choice employer has made me a fantastic offer, and now I don't know what to do. I signed an employment agreement with my current company. Will they sue me if I take the other job? (The other company is not a direct competitor.) How much notice should I give? -Double Jeopardy

More from Fortune

Google's poor social score John Thain's turnaround challenge Breaking up with the Nexus One

FORTUNE 500 Current Issue Subscribe to Fortune

Quiz

Succeed in your new job?

Whether you're changing positions mid-career or starting your first real job out of college, new hires face common pitfalls. Do you know how to avoid them?

1. Five minutes from now, you will step on to an elevator whose only other passenger is your company's CEO, whom you haven't met before. You are most likely to:

Be completely tongue-tied and say nothing.
Introduce yourself and give a 30-second summary of the work you're doing and why you're excited about it.
Chat about the weather.

Dear D.J.: A lot depends on exactly what kind of agreement you signed, says John Robinson, an employment attorney and partner at Fowler White Boggs Banker (www.fowlerwhite.com) in Tampa. An offer letter - which is usually a brief document describing your position, duties and compensation - is generally less binding than an employment contract - which goes into much more detail and usually states how much notice you must give if you decide to quit.

"The rules that govern employment contracts vary from state to state," says Robinson. "So have a lawyer in your state look at what you signed and advise you. But I've been doing this for 30 years, and I've very rarely seen lawsuits against departing employees in this kind of situation. Even if technically the company is entitled to sue you, most often they won't - because they know that, if they get litigious with employees, no one will want to work for them."

What's more, "few employers really want to keep you if you don't want to be there," Robinson says. "You won't do your best work if you'd rather be someplace else. So just be honest and say, 'I'm sorry, but my dream job opened up and I really feel I have to take it.' Most often they will just let you go. One thing in your favor is that, after only two weeks on the job, it's probably not too late for them to call their No. 2 choice and replace you."

The fact that you're not jumping ship to join a competitor should help, too. Many employment contracts contain non-compete clauses that prohibit you from working for a direct rival for a given period of time after you leave your job; but even if your written agreement has one of these, it doesn't apply here.

And non-compete clauses are a sticky wicket anyway: Courts tend to side with employees when these cases do come to trial. Many judges' written opinions over the years have stressed their reluctance to limit anyone's right to make a living, especially when the wording of the non-compete clause is considered overly broad or too vague. This is another area where it matters what state you live in, by the way. "California courts have been extremely reluctant to enforce non-competes, while Florida is very strict and often favors the employer," notes Robinson.

If the document you signed specifies how much notice you have to give, then give the required amount.

"Even though you're leaving, live up to as many of the terms of the agreement as you can," Robinson says. Your new employer will understand - and may even ask to see a copy of what you signed. The reason: "If your current employer does decide to take legal action against you, the new employer can be joined in that lawsuit, on grounds of 'tortious interference,' meaning that they pirated you away by encouraging you to violate your contract," says Robinson. "So don't be surprised if they want to take a look at exactly what your agreement was."

He adds that, even if they really want you to start right away, "your new employer will probably urge you to give the required notice, 30 days or whatever is specified in the agreement, just to keep things on the up-and-up." If no notice period is given, use your own judgment, but try not to leave your current colleagues in the lurch. It's unethical, and could come back to bite you later.

"In the end, let's face it, slavery was abolished long ago," says Robinson. "No one can make you stay in a job." So invest in a quick consultation with an employment attorney in your state (you can locate one near you at www.lawyers.com), just to make sure your written agreement doesn't contain any ticking time bombs. Then go ahead and take the job you really want. And hey - congratulations!

Have you ever accepted a job, then changed your mind? Did it cause any career problems immediately, or later on? Have you ever signed a noncompete, and do you think it was fair? Post your thoughts on the Ask Annie blog.