The Foil is one of The three weapons used in the sport of fencing (the others being épée and sabre). The most popular of the weapons, foil is what most fencers learn first.
The foil has a flexible rectangular blade, approximately 35 inches in length, weighing less than one pound. It has a small bell which barely covers the hand of the fencer. Points are scored with the tip of the blade as it is a point-thrusting weapon.
The valid target area in foil is the torso, from the shoulders to the groin, front and back. It does not include the arms, neck, head and legs. The foil fencer's uniform includes a metallic vest (called a lamé) which covers the valid target area, so that a valid touch will register on the scoring machine. A small, spring-loaded tip is attached to the point of the foil and is connected to a wire inside the blade. The fencer wears a body cord inside his uniform which connects the foil to a reel wire, connected to the scoring machine. when the tip is depressed it completes a circuit, if the fencers blade also completes a circuit with his oponents lamé the valid touch light is lit. There are two scoring lights on the machine for each fencer. There is a valid touch indicator which is green for one fencer and red for the other and an "off target" light for each which is white. These "off target" hits do not count in scoring, but they do stop the fencing action temporarily.
In order to score a touch with the foil you need to have "attack priority" which means that you have either initiated the action or parried your opponents initiation and counter-attacked. Actions are initiated by the first fencer to extend his arm towards his opponent. Once an incoming attack is parried it only counts if the counter-attack is missed as the priority has shifted to the attacker's opponent. If both fencers intitiate an action simultaneously then no points are scored.
An interesting technique used by experts with the foil is to whip the blade such that it bends and the point makes contact even thought you are basically making a slashing motion, this is dificult to parry as it happens extremely quickly and it can hit you in some unexpected areas (such as your back while you are facing your opponent).