These foils have all a length?"
Hamlet Act V scene ii

The foil is the oldest of the Modern (post 17th Century) sporting weapons. It is very much a 'conventional' weapon, that is, there are strict rules governing what can and can't be done

Primarily, the foil is a thrusting weapon with successful hits only being scored with the point. Also the target is limited to the torso and excludes the arms legs and head. Finally, causing great confusion to beginners (and to some experienced fencers) Foil recognises 'Priority' or 'Right of way'. Put simply, this means that if you attack me, I can't simply use my longer reach to hit you first; I must parry (deflect) your attack and then I have the right to reposte (hit back)

These rules aren't arbitrary but reflect the origin of the foil which was as a way safely to train for the necessity of a duel. The duelling swords of the late 17th century, the smallsword and the rapier were primarily thrusting weapons; they did posses an edge, but were much more effective if used with the point, thus we have the rule that only hits with the point score.

Although convention was to duel only to first blood, death matches were not unknown. The surest and quickest way to see off an adversary was to run him through the lung or some other vital organ all of which are housed in the trunk. This, then gives us the limited target

The rule of 'Right of Way' also sees its origins in training for a duel. If my opponent launches an attack at me to which I react merely by sticking out my arm (counter-attacking) then, although he might run onto my point, his momentum would likely carry his point into my target and with my weapon embedded in his chest I'd be in no position to retreat or to defend myself! And so we have the rule of right of way

Previously, it was assumed that all novice fencers would start with the foil and then possibly elect to train with one of the other weapons. Although several clubs are prepared to start with whichever of the weapons the fencer wants to try , at CdA instruction is in foil; by it's very origins it is designed to train good swordplay and the skills and techniques it instills can all be transfered to the other weapons later