Final answer:
In Unreal Engine, the 'GameMode' class is used to define the game's rules, such as scoring and win conditions. It can be customized to create specific rules for different game types and is specified as the default for the game through project or world settings.
Step-by-step explanation:
In Unreal Engine, the class you would use to define the rules of the game is called the GameMode class. This class is responsible for overseeing the game rules, defining win conditions, keeping track of score, and managing the game's overall flow. An example of when you would customize the GameMode class would be to specify what happens when a player character dies or when a level starts and ends.
The GameMode base class can be extended to create custom rules for different types of games, whether they be single-player, multiplayer, or something more complex. Additionally, the derived class GameModeBase handles default pawn spawning and player state initialization, which can be overridden and customized as per the requirements of your game.
In order to put these customizations into effect, you would typically specify your custom GameMode as the default for your game or level through the Unreal Engine's project settings or world settings. This integration is crucial for ensuring that your game behaves according to the unique rules you've set out.