A stiff-arm fend may cause the tackler to fall to the ground, taking him out of the play. Even if the tackler keeps his feet, it becomes impossible for him to complete a tackle, as he cannot come close enough to wrap his arms around the ball-carrier.
A well-executed stiff-arm fend can be a very powerful offensive weapon. In Australian football, it can allow a player to break free from an imminent pack, often completely changing the direction of play. In rugby and American football, the stiff-arm fend can be effectively used to fend off pursuing defenders, or to create holes in a defensive line to the front. This is particularly important in rugby, where American football-style blocking is not permitted, making a stiff-arm fend the only legal way to physically create a hole in the defence.
The term don't argue was coined in Australia to describe the stiff-arm fend. The term describes what a commentator imagined the ball-carrier might be saying as he shoved his opponent in the face or chest, and is used as a noun.
Ball-carriers in Australian football must be careful to avoid fending opponents in the head or neck, otherwise they will concede a high tackle free kick. High fends will generally be allowed in rugby unless the referee rules that the fend is too forceful, constituting a strike rather than a push.