Build and debug gameplay with the Gameplay Ability System - AbilitySystemComponent placement and initialisation, AttributeSets and attribute accessors, GameplayEffects and modifier calculations, GameplayTags as the control vocabulary, GameplayCues for cosmetics, and the prediction and replication-mode rules that decide whether it works in multiplayer. Use when adding abilities, attributes, buffs or status effects, when GAS attributes desync between server and client, or when deciding whether GAS is the right tool for a project at all.