The summer after my junior year of college, I landed an unpaid internship at a women's magazine in New York City. I was over the moon. This was it. I'd made it. I imagined sitting in on meetings where big decisions were made, finding a mentor among the writers whose work I'd read for years, and being given the chance to report articles of my own (articles that would in turn persuade the editors of my eminent hireability).

Then I started my internship. For two weeks, I folded jeans, transcribed writers' interviews, and screened terrible slush-pile short stories that had been submitted for possible publication.

At this point, I began to doubt the value of the unpaid internship proposition.

I tearfully called my parents and told them I wasn't learning anything. They encouraged me to do something else — and I did, spending the rest of the summer working (for money) as a reporter for a small newspaper in Massachusetts.

Leaving the unpaid internship was one of the hardest decisions I'd made at that point in my life. Weren't internships supposed to be a rite of passage? Was I just being soft? More worrisome, was I short-circuiting my career before I'd even started, stepping off the path that would lead to success with the magazine of my choice?

I was reminded of that uncertainty recently when reading about Ivanka Trump and her unpaid interns' tips for making a no-salaried summer job work. The outcry centered on the hypocrisy of a billionaire heiress who peddles female empowerment and then fails to pay her interns. But it made me curious. What can any intern rightfully expect from her experience — and when is a paycheck one of those things? Are there rules governing any of it?

The answer to the last question is yes, but it gets murky fast, especially when considering the diversity of companies and colleges involved in creating and overseeing internships. Schedule, compensation, intensity, and supervisory style differ wildly from internship to internship. Interns' own objectives play a role, too. It's useful to remember, though, that above all interns should be receiving an education.

Columbia University offers a definition that gets at the philosophical crux of the matter: Internships are "short-term work experiences that allow you to observe and participate in a professional work environment and explore how your interests relate to possible careers … [they] should be substantive learning experiences that provide you with a better understanding of an industry, a position, and of yourself." (Keep in mind, though, that not all interns are students.)

Whether an intern must be paid, however, is a question tied to the exact nature of the work she's doing. The U.S. Department of Labor offers legal guidelines on this point for for-profit businesses. (Nonprofits have no comparable code.) If you adhere to these six criteria, you don't necessarily have to pay interns:

1. The internship experience must be for the benefit of the intern.

2. Interns must not displace existing employees, but work under the close supervision of existing staff.

3. The internship is similar to training that would be given in an educational environment.

4. Interns are not necessarily entitled to a job at the internship's end.

5. Both employer and intern understand that the intern won't be paid.

6. The employer must derive no immediate advantage from the intern's activities, and on occasion its operations may actually be impeded.

The no immediate advantage caveat is key, a "kind of insurance policy, protecting interns against exploitation at the hands of their host companies," says Fast Company.

If all criteria are met, then an internship legally can go unpaid. Otherwise it's on the employer to supply at least minimum wage and overtime pay when applicable. In addition, some states supplement with their own guidelines.

The real world application of these laws has been inconsistent, however, and in recent years unpaid and underpaid interns have been fighting back. One especially high-profile lawsuit — brought against Fox Searchlight Pictures by unpaid interns on the set of the 2010 movie Black Swan — inspired a spate of lawsuits against media companies like NBCUniversal, Hearst Corporation, Fox, and Condé Nast. The lawsuits were based on claims that the interns were doing what should be classified as paid work, with the upshot that some companies changed their policies to compensate interns while others shuttered their internship programs altogether. Fox recently settled out of court and agreed to give a slew of past interns, including the plaintiffs, back pay.

Legally, the tide may be turning against unpaid internships. And statistically speaking, an unpaid internship isn't a great bet. The hiring rate for students with any history of paid internships is 63 percent, according to a survey by the National Association of Colleges and Employers. But the hiring rate for students who complete an unpaid internship is dramatically lower — 37 percent — and nearly the same as for those who don't complete any internship at all, 35 percent. The same survey also uncovered a sizable pay disparity: Paid internship students earned an average starting salary of $51,930 as compared with $35,721 for unpaid internship students and $37,087 for those with no internship experience.

Of course, unpaid internships can pay in other ways — significantly, in college credit. Ultimately it's up to each individual to decide for themselves what's worth it (the acrobatics undertaken by some Washington, D.C., interns offer some eye-opening examples). Looking back on my own experience, I have no doubt that I made the right choice — but also that there are many choices to be made in our long and winding careers. Only time will tell whether they're missteps. Then again, there are many paths that can take you where you want to go.