Hello, RPC functions should only work on actor classes, maybe also on actor components not sure right now. Is your AnimationHelper also derived from the UObject class, I wouldn’t know how that can actually work in networking. So simple solution just move your code over from the helper classes to the character and player controller class. If you want helper classes to outsource some functionality I would advice you to use components instead of uobjects anyways because that’s how the framework is meant to be used, allows you to customize the components in blueprints for example. Usually a good approach in terms of networking is to give the clients as little control as possible and minimize network traffic, if you have client side hit detection run a server RPC on the character that the player hit something, the server then applies damage and calls a multicast RPC to let all clients know they need to apply damage locally as well to trigger the recoil animation. Also your RPC’s are a little bit too universal in my opinion, I would rather have RPC’s like ServerSwingSord and MulticastSwingSord, that way it is easier to avoid malitious data sent from clients and you reduce the data amount for every RPC quite a lot.