The argument for input lag doesn’t hold for local networks. Conceptually, I see two ways to do this.
- You can make a web server alongside your game and give to the players an IP+port to type in their browsers. Benefit: No extra app needed. Drawback: web skills needed & TCP is used. Shouldn’t be a problem on local networks… I think (local networks don’t have a lot of bottlenecks that could cause TCP to go into congestion avoidance).
- Create an app (or see if something like that already exists?) that uses UDP to talk with an open UDP socket from your game’s side. Benefit: UDP – speed boost (which, again, might not be that much better than TCP on local networks). Drawback: Much more things to take care of / develop are needed. Since UDP is unreliable and there are actions you probably want your server to receive, you would also need to develop your own little protocol over UDP.
If you really need to go through the internet, forget 1. Real-time multiplayer games with TCP are hard to pull off. Round-based is fine.