Encroachment is a five yard penalty that’s called when a defensive player moves toward an offensive player before the ball is snapped.  It’s usually one of those things that’s so obvious, astronauts on the space station say “hold your horses, son” and I really hate this penalty because it shows a lack of focus. Anyone can get fooled by the offensive line, but  if you keep your head in the game and watch the ball instead of listening to the snap count, your chances of making this mistake are lessened.