Actor Network Dormancy (AActor::NetDormancy) is one of the most impactful server optimizations a multiplayer project can make, potentially saving multiple milliseconds of server CPU time per frame — especially if your project has a large number of replicated actors that don't change often. During a net update, the NetDriver gathers a list of all the replicated actors relevant to a connection, then iterates over these actors and their properties to determine what has changed and should be sent to the client. An actor's network dormancy controls whether the actor is added to the connection's gathered actors list. Dormant actors are not added to the list while awake (not dormant) actors are added to the list. Iterating over actors and their properties can be expensive, especially for projects with a large number of replicated actors. As a result of this, effectively using network dormancy to filter actors out of the considered for replication list can be a vital optimization for multiplayer projects.