Inherit from GameModulesActor

Game Modules 4 introduces the GameModulesActor class, which has stats, conditions, quests, inventory and equipment lists, along with all the methods required to manage those automatically.
Inherit your Actor class from GameModulesActor to utilize it.
If you are using the visual drag-and-drop Inventory System, inherit from GameModulesInventoryActor instead, which adds a few additional methods required to work with the Inventory System.
The classes are well documented. All of the methods are virtual so you can override them in your Actor class if you'd like to customize things.
The DemoActor class in the Party Based RPG demo game inherits from GameModulesInventoryActor.

Learn more about GameModulesActor here.