Learn how to knife someone in the face without using digital effects with this video tutorial. You will learn how to perform this effect without needing a computer and without actually hurting someone. You will need a hat and two identical knives. Cut the blade on one of the knives very carefully. Next, affix the knife to the hard hat or whatever hat you are using for this trick. The actor throwing the knife should pretend as though he is throwing the knife, but he won't actually be doing it. With the camera, you will do a really fast pan called a swish pan. The camera will end with the second actor wearing the hat with the knife already affixed to it.