A duel is a fight, but it is a very controlled sort of fight. In a duel, two men face each other on equal terms (only on very rare occasions did women duel). Duels follow an agreed upon set of rules, begin at a specified time and are held at a specific place. The word itself comes from the Latin term duellum, a contraction of duo (two) and bellum (war).
Usually, duels didn't happen spontaneously. One man would issue a challenge to another, who would often respond by directing further matters to his second. A second was a friend who came along to help prepare your weapons, make sure the other duelist wasn't going to ambush you and make sure the rules of the duel were being followed. Seconds were also supposed to try to defuse the situation that led to the duel by getting an apology from one party or another. In truth, seconds often ended up fighting each other alongside the main duelists. Sometimes there were thirds and fourths along for the fight as well. In any event, after one man issued a challenge, the seconds would arrange all the details. The process could take days.
When a duel was declared, any weapon could be used, with either the challenger or his opponent given the choice depending on which set of dueling rules was in use. The dueling code of 1777 (which we'll discuss in more detail in the next section) provided that:
The challenged has the right to choose his own weapon, unless the challenger gives his honor he is no swordsman; after which, however, he can decline any second species of weapon proposed by the challenged.
For many centuries, the choice was limited to various types of swords. Later, when guns were used in duels, certain sets of rules indicated that only smooth-bore barrels were acceptable, as opposed to rifled barrels that cause the bullet to spin and give it greater accuracy and range (Holland, pg. 84). Many of the rules of dueling seem designed to prevent death and injury, or at least to reduce the likelihood thereof. For example, duelists were sometimes required to face away from each other, only turning to fire when the proper signal was given. This didn't give them enough time to properly aim their weapons.
The loser of a duel was ultimately at the mercy of the winner, who could choose to spare his opponent's life or slaughter him. Dueling etiquette also gave the winner the right to desecrate the body of his rival in any way he chose. This often took the form of decapitation and the posting of the head in a public place.