How much will one bad letter of recommendation for grad school hurt me if my other two are really good? I did an REU over the summer and really didn't get along well with my advisor and I'm a little bit worried about what he might write in my letter of recommendation. He did offer to write me a letter of recommendation without me asking so maybe that's a good sign but I'm still worried about it. I always felt like he didn't like me very much and also he hardly ever spoke to me. I ended up not accomplishing very much in my project but it was a very difficult project and I'm thinking that maybe my advisor knew that and didn't expect me to get too much done. But anyways how much will it hurt me if I have one letter of recommendation that's not very strong. Other than this one letter of recommendation I think I have a very strong application that's probably worthy of top ten schools but I'm worried that this will keep me out of good schools. Any thoughts?