So there is a Tab in the Class Default with Shows the Properties you can set your an actor to be replicated.
For example in a bullet you want to replicate the movement so the bullet flies on all Clients.
The Parameters can be set in the Event, which is replicated but this must be done in a Multicast so everyone gets to know the Parameters and not only the Server.
So the Movement and the Actor Overall replicate but the variables must be set for everyone.