Fencing
Take the romantic, swashbuckling epics of Errol Flynn, add some rules, protective clothing and an electronic scoring system, and you have fencing at the Olympic Games. Two rivals stand opposite each other and feint, lunge, parry and riposte until one scores the required number of hits to win.
Evolved from the ancient form of combat, fencing is one of only four sports that has been featured at every modern Olympic Games. It was the first to include recognised professionals in a medals competition after modern Olympic Games founder Pierre de Coubertin arranged special events for professional fencing "masters" in the original 1896 and 1900 competitions.
The clothing has become so protective, though, that officials modified masks a few years ago to return a "human face" to the event. Fine, but for intense reality, the 1924 team foil competition still wins: After the Olympic Games, an Italian and a Hungarian settled a scoring controversy with a real duel.