Will Cities: Skylines 2 have multiplayer?

The short answer is no.

The longer answer is that, historically, multiplayer has never been a key feature of citybuilders. Especially not direct, simultaneous multiplayer. There have been games like EA’s disastrous SimCity (2013) as well as Tropico 5 and 6 that have dabbled with competitive and cooperative city builders, but usually, each player builds their own individual city and can trade with others.

There are games adjacent to city builders that sometimes include cooperative simultaneous multiplayer, such as Parkitect. In that game, it is completely possible to mess up the work of another, but there are ways around it. Communication is the most obvious, but you can also outline territories so certain players are only able to build within these boundaries.

However, that’s all moot because Cities: Skylines 2 doesn’t have multiplayer, as Cities: Skylines never did, either. It’s probably just not going to happen. The developers have never hinted it as a planned feature.

A major barrier here might be having to keep the complicated simulation of the game synchronized across two clients. Citizens are tracked, electricity and sewage, traffic accidents and environmental disasters; even the water in the game has complicated physics that are difficult to keep in sync between two separate games. Most multiplayer titles try to reduce how much data has to be sent across the internet by having most of the game processed on each client, and with a simulation like this, it’s simply not possible. That would be why most multiplayer builders have each player isolated to their own build.

Never say never, but you have my permission to say “doubtful.”