Factorio

I did not expect to love Factorio as much as I do. Factory games should not be my thing. But there is something about building a production line with someone else where you each own a section of the problem that gets its hooks in fast. One person handles iron smelting, another figures out the green circuit chain, and three hours later you are both staring at a pollution map arguing about train routing. For a LAN party, this is the game you run when you have a full weekend and a group that enjoys planning as much as playing. The multiplayer is rock solid and supports up to eight players on a shared world without complaint.

Factorio is the game that turns my most competitive friends quiet and my most patient friend into the group's de facto factory architect. There's no PvP here, no elimination, just a shared production line that keeps getting more complicated until someone finally launches a rocket at four in the morning. It's not the loudest game at a LAN, and if your group wants shouting and chaos, this isn't it. What it offers instead is the rare kind of session where four people are all staring at the same problem, quietly arguing about belt throughput. Setup over LAN is smooth and reliable. The learning curve up front is real, so give newcomers a short tutorial run before diving into a shared save.

Factorio is the only game I have started at 9pm and looked up to find it was 2am without any sense that time had passed. The loop is gather, build, automate, expand, and then do all of it again at a larger scale. On modest hardware it runs well for most of the game. The catch is late-game megabases. Once your factory covers half the map, weaker CPUs start to feel it. Keep your builds focused and it holds up fine. If you want a game that rewards systems thinking and does not care about graphics, this is the deepest option on the list.