On defense in American football, rushing is charging across the line of scrimmage towards the quarterback or kicker in the effort to stop or "sack" them. The purpose is tackling, hurrying or flushing the quarterback, or blocking or disrupting a kick. In both college and professional football, getting a strong pass rush is an important skill, as even an average quarterback can be productive if he has enough time to find an open receiver, even against a good secondary. To increase pressure, teams will sometimes use a pass-rushing specialist, who is usually a quick defensive end or outside linebacker tasked with aggressively rushing the quarterback in obvious passing situations.
One of the most effective methods of rushing the passer is by using a stunt or twist, which is when defensive players quickly change positions at the snap of the ball and engage a different blocker than the offense expected, Defenses typically task three or four defensive lineman to rush the passer on most plays, but most will occasionally increase pressure by blitzing one or more non-lineman at the quarterback when a pass play is anticipated.
A pass rush can be effective even if it does not sack the quarterback if it forces the passer to get rid of the ball before he wanted to, resulting in an incomplete pass or interception. To attack a strong pass rush, offenses can throw quicker short passes or run draw plays or screen passes, which are design to lure defenders into the offensive backfield and then quickly get a ball carrier behind them.