How important are standard grades when applying for Universities?

Is it delusional to apply to a top American university as an international student with average-to-bad grades?

• Hello. I want to study (international student, won't be applying for financial help) computer science at Caltech, Harvard, Stanford or another high ranked American college. My grades in high school go from great (in English) to mediocre (Social Studies, Spanish) and good but not outstanding (Math, Physics). In my class, I rank among the top ten out of almost fourty. That doesn't make me competitive enough for those universities, so I'm going to rely on extracurriculars, recommendations, summer jobs, a portfolio that shows my skill in CS, volunteering, essays. Do you think I stand a chance? Should try less prestigious universities and forget about the Ivy League? Are grades more important than whatever I can show the admission people? What should I do to stand out if my results aren't competitive?

• Answer:

  If you are using the term delusional in its medical sense, then no. If you wish to waste time, energy, money and emotion on something that is a choice you are making that is not unlike those who play the lottery and think they just might win. But the lottery is random. With the selective admission process it may seem arbitrary at times from the outside but a great deal of thought goes into selecting which people and which groups get in. The only reason you should apply is if you have a huge hook. Given what you have said about yourself I am not sure you fall into any of the under-represented groups who get treated differently, nor does it seem you are a world class athlete. The one  category left that sometimes works is money, but it has to be a huge amount you would have to have and have to be willing to part with to the university. Major donors get special treatment. I just heard about a student this year who was denied initially.   Dad flew in and told the admission dean he'd give a million. Decision changed. I can't swear to veracity of this obvioulsy but the details were so specific on all the players that it has the smell of truth.