During my graduate school days (MS, mathematics, 1982), we were required to get a B or better in all classes. I did receive one B- that in retrospect must have been charity on the prof’s part. I suspect that, with a reasonable student, most professors won’t give a C unless you really screws the pooch. After all, without grad students, the professors might actually have to do actual work…
Grades mattered at the grad school I attended for a couple of reasons.
To stay in the school you had to maintain a 3.0 overall average. To keep an assistantship, you had to maintain a 3.5 (I think, but don’t remember - it might have been higher, like a 3.7 or 3.8).
BUT, once I was finished and interviewing for jobs, it didn’t seem as important. What was more important was that I graduated with an ALA accredited degree - at least that’s how it seemed to me, from the prospective employee’s point of view.
Well yeah, most/all grad programs require a 3.0 or higher. But undergrad (where I live) requires a 2.0 or higher and high school required a 0.3 or higher. However in undergrad and high school there is intense competetion to get high GPAs since those GPAs determine your next education level. High school GPA plays a role in what college you get into, college GPA plays a role in what grad school you get into. But once you get to grad school what incentive is there to get As anymore?
Exactly. However, I feel we should distinguish two types of graduate school experiences. The first is the terminal Masters degree. There are a fair number of people doing this, they mostly go to class, do a fairly short thesis, then get a job. Perhaps grades are more important in this population. Then there are PhD students. Once you pass your quals and get an adviser and research topic, grades don’t count at all, and you’ll probably get a 4.0 without even thinking about it. (Or caring.) At this level it is all politics. You need to hook up with the prof with the grant money, who has assistantships, can afford to send you to conferences, and has some connections to get you a job. You need to avoid antagonizing people who can make your life difficult. Depending on your druthers, you need to pick a topic that is useful to your prof, where your research is well defined, or you need to invent something you enjoy.
So, the real incentive to get As is to gain the reputation as a really smart student, the kind the top professors would like to have work for them. And for this, participating in seminars run by the prof you want to work for is real important. Getting a B in a subject the prof doesn’t care about counts less. Getting all Bs is not a good idea.
I loved grad school. (I stayed there long enough. 
)
grades matter alot . . . i think those rumour are paper chase bs, I never heard of anyone tearing pages out of books - (would be enough to get you kicked out of any decent lawschool) - nowadays when you can get almost anything you need on-line, the library is just a quiet place to plug in your laptop. people are very stingy with notes, outlines, etc. though, but, as for lawschool, grades are very important, particularily your first year
I heard similar things, in a music course. Sure, there were people who went to the public library and got a book for a month that we could only get for 24 hours from the uni library - but fair enough, they got the idea first. We all went to the pub instead. And we got better marks anyway 
…
I’m in a history grad program. MA completed, and in the dissertation phase of the PhD.
My department doesn’t do grades, period. For the MA part of the course, you just get a Pass for any course you completed, and then a Pass for each of your four comprehensive exams and orals. The general rationale behind this, i was told, is that the department only accepts A students, and if your work is not of sufficient quality then you won’t last in the program. So they see no need to give letter grades. Also, our department does not have a terminal Masters degree; they only offer the MA for people in the PhD program; most programs that offer a terminal MA do have grades.
In my field, particularly for those who want to go on and be academics (i.e., most of us, in my department at least), the key to getting a job is a good dissertation, hopefully a publication or two, teaching experience, and good recommendations from respected professors.