Hey everyone,
I’m looking for some advice on how to properly structure replication in a project that wasn’t originally built with multiplayer in mind.
A while back I tried adding replication to a different game project and ended up shelving it due to how tedious it was—felt like I had to rewrite entire systems just to make things sync properly.
Now, I’ve got a first-person shooter I’ve been working on casually in my free time. I’ve recently decided to make it multiplayer, which I know is kind of backwards—ideally, multiplayer should be planned from the beginning. But here I am, and it’s too late to start over.
So, my main question is: How would you go about retrofitting a singleplayer-focused project to support multiplayer in Unreal Engine?
To give a specific example:
Let’s say I have a weapon with an OnFire function that gets called whenever the gun shoots. In singleplayer, this is super clean and self-contained:
But once I start replicating this, things get messy. Logic ends up split between Server, Multicast, and Client RPCs, and I lose the clarity of a centralized function. Everything feels scattered across the replication flowchart and harder to maintain.
I’m wondering how others approach this—
Is it possible to still keep most of the firing logic inside OnFire, and just call it from RPCs (like Server_OnFire, Multicast_OnFire, etc.), branching internally for authority checks? Would this also work correctly for listen servers, where the host is both a server and a client?
Would love to hear how you all handle organization and structure for multiplayer in projects that didn’t originally plan for it.
Any best practices or examples are appreciated.
