I've been looking for examples on this, though I guess I just have the wrong keywords. If someone can direct me to the hub of a good resource, I'd be thankful.

One element I'd like to add in a game is client-only gameplay. That is, they go into an instanced dungeon for them only. There's no reason for the server to know what their z-level is, or what action they're doing, or if they're even alive. The server would just know that they're in a dungeon, and when they're finished.

Is it possible to do something like that? "Isolate" some updates from the client-server relationship, so that the server only gets information that it needs? My hope is that there would be less lag if they didn't send so much information back and forth. Sure, I'd still be calling Say "Thisandthis" every now and then, so there would be some server chatter, but there's a lot that only the client needs to "know".