This armored combat sport is called Buhurt (or Bohurt). People new to this sport should check out https://www.startfighting.info/ for a more in-depth introduction.
In general, there are 3 different categories in this sport: Duels, Melees , and Profights / Elite Fights. Each of these are described briefly below. Prior to attending any event, it is highly recommended that you review the rules that govern that event (either Buhurt International or the IMCF rule sets are two main ones used).
Duels involve two fighters (1v1) and include the following categories: longsword, sword and buckler, sword and shield, and polearm. In Buhurt, these are timed rounds and the fighter with the most points earned through solid strikes wins.
Melees are team fights where each of the two participating teams consist of three five, ten, or more fighters battling within the list. Each person counts as a point. If a fighter falls to the ground, they are out and there team loses a point. The team with the most points (fighters standing) in the end wins.
Similar to duels, profights are between two combatants. Profights permit kicking, punching, grappling and are best described as mixed martial arts (MMA) in armor. Points are awarded based on solid strikes and by knocking your opponent to the ground.