Worst-case scenario: the UEd Goblin wipes the map and burns down your house.

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Object >> Interface

Package: 

Core

Known direct subinterfaces:

CustomPropertyItemHandler, EditorLinkSelectionInterface, GameCrowdSpawnInterface, GameCrowdSpawnerInterface, GameStatsDatabaseVisitor, Interface_NavMeshPathObject, Interface_NavMeshPathObstacle, Interface_NavigationHandle, OnlineAccountInterface, OnlineCommunityContentInterface, OnlineContentInterface, OnlineEventsInterface, OnlineGameInterface, OnlineNewsInterface, OnlinePartyChatInterface, OnlinePlayerInterfaceEx, OnlinePlayerInterface, OnlineStatsInterface, OnlineSystemInterface, OnlineVoiceInterface, UIDataStoreSubscriber, UIEventContainer, UIListElementCellProvider, UIListElementProvider, UISettingsClient, UIStringRenderer, UIStyleResolver, UITickableObject

This interface in other games:

UT3

The base class for all interfaces. Interface declarations without an explicit parent interface extend this class.

Technically this is a class extending class Object, but you should really treat interfaces as not being in the class hierarchy. Keep in mind that class limiters strictly limit a class reference according to the class hierarchy, not according to any implemented interfaces.