CodeMasters are extremely talented players who become designated leaders of a respective BattleDrome. After playing in a CodeMaster's arena seven times they are required to challenge you to a match. Facing and beating a CodeMaster is one of the most sought victories, as doing so will unlock new Locations, Creatures, BattleGear, and Mugic; however, they also have other duties to Perim than just challenging opponents. As shown in "Fighting Friendly," they also have the responsibility of making decisions that influence the players of the game, and in "A Rare Hazard" we see they also are responsible for disciplining other Chaotic players as well as solving serious player-related problems in Perim, like when certain players began stealing weapons to destroy locations. In the beginning of "Last Stand," they recall all of the players from Perim and shut down the transporter system for the players' safety. In this sense the CodeMasters are much like the "Administrators" of Perim.
An interesting point is that rearranging the first letters of all CodeMasters' names forms CHAOTIC. Another arrangement would spell Cothica.