Some advice shamelessly stolen from Ian Garforth...
Epee is easy to understand. Both fencers are wired into a box. When one of them hits their opponent, their light comes on to show they’ve hit. It doesn’t matter where on their opponent they hit – they can hit them anywhere.
Whoever hits first gets the point. Sometimes, they might both hit each other at the same time, in which case both lights come on, and both fencers get a point. The first to a total (5, 10, or usually 15) wins. Epee referees have to be able to operate a stopwatch and count and not a lot more. Sabre is different. Firstly, the target area is everything from the waist up (though not including the hands, or, I suppose, technically the back of their head, but if you manage to hit the back of their head in a sabre bout, there’s something peculiar going on. Are you sure you’re at the right end of the piste..? :o) )
Having said that, if you hit an ‘off-target’ area, nothing happens. Nothing goes beep, and no lights come on. You just carry on. As if nothing’s happened. Which it hasn’t. However, if you hit each other at roughly the same time, the referee has to work out who was attacking and who was defending. The attacking person gets the point. Perhaps the ref thinks you were both attacking. A ha. Then he has to work out who was attacking first, and that fencer will then win the point.
So how does the referee establish this? The beginning of the attack is defined as a forward motion of the attacking hand. Do this first and it’s your priority. You get the point. Unless… Unless what? Unless your opponent gets priority back. How? By parrying your attack. Then they have the priority, and it’s time to get the hell out of Dodge, or win the priority back. How? By parrying their attack. There’s a pattern here which the sharper reader may have observed… One more thing to consider. When you hurl your attack towards your opponent, your attack ends when your front foot hits the floor. If you have not scored a hit by now, you may have an issue, as, again, priority has passed to your opponent. Foil uses the same principles for priority as sabre, but the target area is different. The target areas are described in more detail in a different article.