Do colleges and universities consider the difficulty of your courses taken in high school?

Yes, absolutely. Schools prefer students who challenge themselves. I have students who sometimes ask if its better to stay in regular classes vs. moving up to honors or AP, because they know they can maintain a better GPA. The truth is, many schools consider the difficulty of your courses just as much, if not more than your GPA. That being said, if you are getting C's and D's in an honors or AP class, you should either get a tutor or talk with your guidance counselor about whether those classes are too difficult for you.