I need to be able to scan the terrain in front of my player. If the terrain is too steep, my player should be unable to walk up. Can anyone give me a general guideline on what my code should look like to accomplish this? Thanks

Put an invisible blocks.

use c_trace in front of your player

Ive never tried this but if you check the "normal" variable after a c-trace
in the forward direction, you can get the angle of the surface ahead of you with
some processing like vec_to_angle(tempVec,normal); or something.
If the (tempVec) x or y angle is to steep (say > 45 degrees),
then block the movement somehow.

Hope this is of some use.