For those unfamiliar with the concept, Arenas are the peak of small-team competitive PvP. Grab a team of 2, 3, or 5 players and fight against equally matched opponents to determine who's the best.
WildStar Online arena matches consist of two teams with shared respawn pools. Teams start with a certain number of lives, and each time a team member respawns the shared pool decreases by one. This makes for extremely tense matches, especially as they near their end. Does the other team have a tank who's more annoying than dangerous? Ignore him and repeatedly kill the healer until the team's out of lives, then take your time with the tank. Down for the count with 1 shared respawn left? Maybe you should stay down so your team's top damage dealer can use the final respawn for a last stand.
Arena-rated PvP gear has rating requirements attached to them, ensuring that you prove your skills before being able to purchase a specific piece of gear. This also means that as you improve your rating, you'll face off against opponents with similar gear, keeping the matches as close as possible throughout your Arena trials and tribulations.