LIKE a lot of other college seniors, Alexandra Leumer got her introduction to the heady and hazardous world of law school scholarships in the form of a letter bearing very good news. The Golden Gate University School of Law in San Francisco had admitted her, the letter stated, and it had awarded her a merit scholarship of $30,000 a year — enough to cover the full cost of tuition.

To keep her grant, all that Ms. Leumer had to do was maintain a grade-point average of 3.0 or above — a B or better. If she dipped below that number at the end of either the first or the second year, the letter explained, she would lose her scholarship for good.

“I didn’t give it much thought,” she said. “I didn’t think it would be a challenge.”

Her grades and test scores were well above the median at Golden Gate, which then languished in the bottom 25 percent of the U.S. News and World Report annual rankings of law schools.

How hard could a 3.0 be? Really hard, it turned out. That might have been obvious if Golden Gate published a statistic that law schools are loath to share: the number of first-year students who lose their merit scholarships. That figure is not in the literature sent to prospective Golden Gate students or on its Web site.