[quote name='hplus0603' timestamp='1348765928' post='4984406']
If you want to avoid players cheating the rules, you have to write the game logic on the server.
If you want to provide a good user interface, the user interface also has to know about game logic.
If you want to avoid players cheating by "knowing too much," you have to be careful about what information you send from the server to a client -- just because you don't display something like the cards in the opponent's hands on the screen, doesn't meant that the client won't "know" it. Assume everything in memory in your client is visible to the player.
You can use an existing server framework, or roll your own, or use a middle ground like Node.js or WSGI or whatever. It's really up to you -- there's no "wrong" answer here. Especially for card games, trying to predict movements or minimize latency isn't really necessary, so the tricks and restrictions of action games largely don't apply.
Thank you. I understand where game logic have to be. But i'm not sure what to choose, to write the server or to get an existing one. Does writing a server on Node.js costs a lot of time, because i hear about it for first time? You've got more experience. It will be my first online game and it's hard for me, because i don't know where to start.