One in the Chamber BattleArena comes pre-installed with a one in the chamber module which adds an ability for players to one-shot others when a bow is used. Additionally, any time a player scores a kill on another player, they are granted an arrow. An example arena can be found here . Configuring the Module This module can be enabled by adding one-in-the-chamber to the  modules section of your Arena Configuration . No other configuration is required from this point, and once BattleArena has been reloaded with  /battlearena reload , the arena this module is configured on will support one in the chamber.