SG5. Fair: The exclusive AI execution prevents from interceptions of other AI programs, and the read-only state prevents changing of the game state illegally. GAIA provides a feature to execute AI programs exclusively and several immutable classes. However, GAIA cannot help adding new immutable classes that represent the game state. Thus, we decided to use Scala to develop game software for JC2012 because functional programming languages including Scala prefers immutability and supports immutability.