This tutorial guides you through setting up the Gameplay Ability System (GAS) in Unreal Engine. You’ll learn how to add GAS to your project, create an Attribute Set to manage health, and integrate it with your character. You will also learn how to create a Gameplay Effect to apply damage, and a Gameplay Ability to trigger that effect. By the end, you’ll have a character that can damage and kill other actors in the scene.
https://dev.epicgames.com/community/learning/tutorials/eBEK/unreal-engine-getting-started-with-gas