Here, I will answer what sounds the most realistic. TGC will for sure not pay for public servers so you can host your game there, and the only way you can have a game where you join a server is if you code, which is mightly complicated and no one want's to do that.
So what I think is the most reasonable answer is that the multiplayer edition will be that you join through Ip's. You can create, or host a game, and people can join. One way that you can let people know of which Ip's to join, is meaby creating a website where people can post their Ip's which they are currently hosting a game, and then from your game, people click a link to go to the site to see which game to join.
This is the most reasonable answer, and there is no other way of doing online multiplayer than the ways I have said above.
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