Law School Discussion

I've been lurking around this website for quite some time in hopes of answering some of my questions concerning Law School. I read someone's comment on here, which stated that high school grades matter to law schools and I was wondering if that's really the case. I am currently a senior in highschool and I haven't exactly showed what I am really capable of and I'm worried now that I might not make it into a law school due to my failures for the past three years. So do law schools actually check your high school transcripts and have it play into their decision to accept/reject you from their school? Thanks in advance.

edit Thank you very much for your helpful replies. I can now sleep at night.