There are three stages in the sport of eventing: dressage, cross-country, and show jumping. Eventing is basically a triathlon for horses and their riders. While these three events are practiced across many first-world countries, the rules are slightly different for each area. The following information pertains to America.
The first stage of eventing is dressage, where the horse is ridden in an enclosed area and is judged on suppleness, balance, and rhythm. Most importantly, the horse and rider are judged on how well they work together.