In the dictionary, a champion is defined as someone who has won first place in a competition, or someone who fights for a cause. In the SCA, a champion is both.
Many groups, local and kingdom, have official champions. They can be for heavy list, fencing, or a variety of arts and sciences. Champions may win a tournament, be selected for their skill, or singled out for their chivalry and courtesy. Champions are largely symbolic and may form part of the royal or noble retinue and stand behind the thrones. Martial champions are charged with guarding their ruling nobles. Champions may be responsible for serving as an example of good behavior to the populace and promoting their art or skill.