Fencing can be thought of as the refined remnant of an aristocratic code of manners and revenge. In fact at the 1924 Olympics a dispute of honour between Italian fencer Oreste Puliti and Hungarian judge Gyorgy Kovacs boiled over at the Folies Bergère night club and resulted in a real duel that left both injured.
Fencing bouts are just three minutes long, and decided by intricate footwork, subtle flicks of the blades and sudden explosive movements.
The rules are fabulously complex. Basically the winner is the fencer who scores the most hits on their opponent, but there are key differences between the three types of sword used: foil, épée and sabre.
Foil is the lightest sword. Foil bouts are tense, balletic, refined affairs in which competitors can only score points by hitting the torso: no arms, legs or sensitive areas allowed. There are also rules about "right of way", which come into play if both competitors score a hit. Only one of those hits will actually count. Simplifying things massively, the scorer will be the one the referee deems to have held the tactical initiative: launching an attack first or having just neatly parried your opponent would count.
Epée uses a slightly heavier implement, allows you to hit wherever you like, and doesn't bother with the right of way rules - so it's all about counterattacking, and double hits are allowed so long as you make contact within 40 milliseconds of your opponent. Historically this discipline was designed to more realistically mimic proper, to-the-death duels.
Sabre is different again. The target area is everything above the waist, except the hands - and unlike the épée and foil, fencers can use the blade of the sword to score points, not just the tip. Right of way rules are in force. What this all boils down to is a bout based on quick forwards and backwards footwork with not much parrying. Blink and you miss it!
Fencing might be insanely complicated, but it's very easy and fun to watch, mainly because of how it's presented: you know when someone's scored a hit because their section of the strip, and indeed their helmet, lights up either red or green.