From the SCA Newcomers Portal:
Rapier combat in the Society attempts to recreate styles of swordfighting from the later part of the Middle Ages, often based on manual and theories of combat that have survived to this day. Rapier combat uses a foundation of style and finesse that has since evolved into the modern sport of fencing. Unlike the modern sport, our combat uses a wide variety of weapons and body protection and our combat takes place with freedom of movement in any direction. Rapier combat can be found in both tournaments of individual and team combatants and in larger melees and wars!
Like armored combat, rapier combat in the Society is based on a system of honor and chivalry. Because the combat is full speed and unchoreographed, the combatants themselves determine if the attacks they receive were successful based on the angle, location, and force of the strike. Safety officers, known as marshals, are always on hand to ensure that the combat is performed safely and to ensure that all equipment used meets established safety standards.
Weapons and Armor
Weapons used in rapier combat are made out of safe, unsharpened steel capped with rubber and foam safety tips that ensure no actual cutting or puncturing takes place. There are a wide variety of these blades that range from small daggers to large, two-handed great swords. Additional, other implements such as bucklers or small shields, capes, canes, and more can be used to block and parry attacks.
Protective clothing is required for all rapier combatants. This clothing ranges in style and material based on Society and kingdom standards, but in general all combatants wear protection across their whole body, including their head and neck. This may include thick, padded clothing such as coats or gambesons, or more rigid armor such as mail or scale.
Cut and Thrust
In recent years, a new type of combat has undergone development across the Society called “Cut and Thrust” combat. This style of combat could be considered a hybrid of armored and rapier combat that involves more stringent protection standards including more rigid armor than rapier combat but still uses unsharpened steel blades instead of the rattan of armored combat. Cut and Thrust is still in an experimental stage in many kingdoms and may not be available in all.