The foil is a descendant of the light court sword formerly used by nobility to train for duels. It has a flexible, rectangular blade approximately 35 inches in length and weighing less than one pound. Points are scored with the tip of the blade and must land on valid target: torso from shoulders to groin in the front and to the waist in the back. The arms, neck, head and legs are considered off-target. Hits to this non-valid target temporarily halts the fencing action, but does not result any points being awarded. This concept of on-target and off-target evolved from the theory of 18th-century fencing masters, who instructed their pupils to only attack the vital areas of the body - i.e. the torso. Of course, the head is also a vital area of the body, but attacks to face were considered unsporting and therefore discouraged.
Although top foil fencers still employ classical technique of parries and thrusts, the flexible nature of the foil blade permits the modern elite foil fencer to attack an opponent from seemingly impossible angles.
Competitors often "march" down the fencing strip at their opponent, looking to whip or flick the point of their blade at the flank or back of their opponent. Because parrying (blocking) these attacks can be very difficult, the modern game of foil has evolved into a complicated and exciting game of multiple feints, ducking and sudden, explosive attacks.
For newcomers to foil fencing, one of the challenging concepts to grasp is the rule of right-of-way. Right-of-way is a theory of armed combat that determines who receives a point when the fencers have both landed hits during the same action. The most basic, and important, precept of right of way is that the fencer who started to attack first will receive the point if they hit valid target. Naturally, the fencer who is being attacked must defend themselves with a parry, or somehow cause their opponent to miss in order to take over right of way and score a point. Furthermore, a fencer who hesitates for too long while advancing on their opponent gives up right-of-way to their opponent. A touch scored against an opponent who hesitated to long is called an attack in preparation or a stop-hit, depending on the circumstances.
Additionally, the referee may determine that the two fencers truly attacked each other simultaneously. This simultaneous attack serves as a tie- no points are awarded, and the fencers are ordered back en garde by the referee to continue fencing.
