A duel is a formal, prearranged fight between two people, historically fought with weapons like swords or pistols to settle a dispute or defend personal honor. In centuries past, if someone felt insulted or disgraced, they might challenge the offender to a duel. The two would meet at an agreed-upon time and place, often with witnesses called seconds, and fight according to strict rules.

Famous duels include the 1804 pistol duel between Alexander Hamilton and Aaron Burr, where Hamilton was killed. Duels were eventually outlawed in most countries because they led to unnecessary deaths over matters that could be resolved peacefully. By the late 1800s, courts and legal systems replaced dueling as the proper way to settle disagreements.

Today, the word duel describes any intense, head-to-head competition between two opponents. Basketball players might duel for the scoring title. Chess grandmasters duel over the board for hours. Campaign rivals duel in debates. Political analysts called the 1960 Kennedy-Nixon debates “the Great Debates,” but they were really duels of wit, charm, and persuasion. When two talented people compete directly against each other, giving everything they have to win, that's a modern duel.

The word duelist refers to someone who participates in a duel.