A foil is the modern version of a rapier. It is about 35-in (88.9 cm) long and weighs less than 1 lb (.45 kg). It is a point weapon, which means that only the point of the blade can score a valid touch. The target area for a foil is the torso (the area covered by the jacket), not including the head or arms. Any touch scored outside of the target area (off-target) is not valid. Foil is also a "right-of-way" weapon, which means:
- One fencer makes a threatening move, usually a straight arm toward the other fencer within striking distance. This makes him the attacker and gives his actions precedence (right of way).
- The defender must remove that threat by a block or parry (remove the right of way) before he can counterattack.
- The counterattack then has right of way until the initial attacker defends himself.
- The cycle continues until a touch is recorded.
- The point is awarded by the director observing the bout only if the touch landed on-target or the attacker had right of way.
For electric scoring, a foil fencer must have a metallic vest (lamè), an electric foil and a body cord. The lamè is worn over his jacket and covers the target area. An electric foil has a button on the end with three wires (A, B, C) running down the blade to a connector behind the bell guard -- the round, silver part of the foil that protects the hand. The body cord connects the foil and lamè to the reel. Also, the strip is covered with a metal grid called a piste.
For foil, there is a closed electric circuit set up by the system, which is opened when a touch is landed (the button on the foil is depressed); when a touch occurs, a buzzer goes off and a light lights up on the side of the fencer who was touched. The button must be depressed by 0.1 lb (0.5 newton) of force; this is tested before the bout by placing a 500-g weight on the tip of each fencer's foil and seeing if it triggers a light on the machine. The foil's A wire is connected with the target lamè, the B wire is the "hot wire," and the C wire is the return current; the piste and the bell guard are electrically grounded. When the foil (B) touches something, then one following situations can happen
- B touches piste or opponent's bell guard (ground) - no lights, nothing happens, play continues
- B touches the opponent's lamè (A) - a colored light lights up indicating a valid hit
- B touches non-metal part of the opponent (C) - a white light lights up indicating an off-target hit
- B touches non-metal part of the opponent (C) and then touches the lamè (A) within a fraction (1/20) of a second - both lights light up indicating that an off-target hit occurred before a valid hit; no point would be awarded
After the lights go off, the director stops the action, recounts the last series of engagements, determines which fencer had right of way and awards the point. Often, lights go off on both players (simultaneous touches) and the director must sort out the action, determine if either player had right of way and award points, if one or both players made valid hits. In foil, no points are awarded if both players make simultaneous valid touches. Once the point has been awarded, the director moves the fencers to their starting positions and continues the action; if no point was awarded (for example, if there were an off-target touch), play resumes from where the touch occurred.