Do you know the rules football? Well, if you do not then it is a good thing you took the time to read this because I am about to tell you. First, you can not foul anybody or that is a five yard penalty depending on the foul.
Another is defensive pass interference and if you pass interfere somebody the get an automatic first down and the ball is placed wherever the pass interference took place.
Another is offensive pass interference which is when the receiver pushes off on the guy that is covering him and some other things, but that is just an example of what you can not do.
The last one that I am going to talk about is face masking. This is when the guy on defense or offense grabs a hold of the face mask and depending on how long he holds on is either 5 yards if he grabs it and lets go or if he grabs it and does not let go right away it is a 15 yard penalty.
Those are only some of the things that you can not do. There are plenty more that I won't go into, but as long as you get an idea of what you can't do.