The built-in “Any Damage” event is authority only, so it will never run on the client. This is OK though, generally the server should be the only one that actually applies damage to characters, and the clients can find out about the health change if the health value is replicated. If you’d like clients to react to the health change, perhaps to play an animation or sound, one option is to set the health variable’s replication to RepNotify. This will create a corresponding On Rep function that will be called automatically when the server changes the value.