In my last game, I did movement and animation so that the characters moved x pixels per frame, etc, and capped the framerate. In the current one I''m planning to do movement so that it moves x pixels per second, so I will be multiplying speed by velocity to get distance. But I was thinking that for collision detection, this could present a problem, because the sprites might move through each other, and not ever touch if it is running on a slow system, but a collision should have still occured. How would I do collision detection that searches for a collision along a path instead of only at the exact location of the sprite? I have heard a little about vectors, but I am not quite sure how to do this... Thanks ----------------------------- "Truants move on, cannot stay long, some die just to live" From Immortality, by Pearl Jam http://www.crosswinds.net/~uselessknowledge