World of Warcraft offers an arena system where players can create teams and fight other players. Participating in rated arena matches earns points that players can use to buy equipment that in turn makes them more formidable in the arena.

Teams that compete in an arena are assigned a rating of 1500 to start out, and their rating goes up when they win matches and goes down when they lose matches. Teams that are average to below average get roughly the same number of points, and higher rated teams get a lot more points than average teams. A team that maintains the default 1500 point ranking gets 344 points for the week. A awful team with a rating of 1250 gets 289 points. A team with a good rating, 1750, gets 683 points, and an outstanding team with a 2000 rating gets 1054 points. Here’s the scale on a graph (from here:

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Most teams have a rating around the 1400 mark, as you can see from the graph that follows (borrowed from here):

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What players soon figured out is that good teams could give (or more often, sell) arena rating to people.

Players can get points for playing as few as 3 games per week (the rules for who’s eligible for points are complex and aren’t worth going into), and it’s tough to lose more than 20 points in a game. So really good teams were selling spots on their roster to inferior players, lending them their rating for the week and giving them more points than they could come by honestly.

When Blizzard kicked off Arena Season 3, they wanted to limit certain “showy” rewards to the top arena players, and put a minimum rating of 1850 on weapon rewards and 2000 on shoulder armor (because they’re fancy looking). To prevent people from getting these rewards without beating other good teams, they created a personal rating that is adjusted from match to match along with team rating. So every time a player wins a match, their personal rating goes up, and every time they lose a match, their personal rating goes down.

You may be able to guess how players responded. Matches are made based on team rating, but the reward limits were based on personal rating. Players would fill their team with characters with disposable ratings, then intentionally lose to drive the team’s rating down. Then the good players on the team would log in and win against inferior competition, raising their personal rating. A player with a personal rating of 1800 would be playing matches set up for a team with a rating of 1200 or 1300, enabling them to get fat playing against poor competition.

Last week Blizzard instituted a new rule that prevents players from buying their rewards if their team rating and personal rating aren’t within a certain range. I can’t wait to see what the players come up with next.