how do make multiplayer game for PC

Hello How can i make multiplayer game in unity 3d, i mean that my friend will launch game and can choose multiplayer and than play with me?

This is a very broad topic, and there is no simple answer.

It's also not a project that I'd recommend starting with if you are new to programming, or to Unity. First you need to get familliar with the basics of game programming, and of how Unity works in particular, and then you can start considering more complex fields of development such as multiplayer.

However, if you are ready to move to that stage, here are a couple of good places to start learning about Unity's networking:

The Unity Multiplayer Networking Manual Pages

Leepo's Networking Tutorial (PDF)

Free unity multiplayer game sources:

i heard of some people doing something with smartfoxserver pro.... i dont know where to get it but im sure u can google search it

Click this link and download smartfox trust me its for multiplayer http://www.smartfoxserver.com/labs/API/

and heres a tutorial for it http://www.youtube.com/watch?v=qD9RxZaXByo