They play chess! and I think that if it wouldn't be too complicated... There should be a basic chess gambling system, PvP of course!

Given the number of users that I believe would ever use it (I'm thinking, less than 1%.... probably significantly less) I'd suggest the time would be better spent elsewhere and the few users that do enjoy a good game set up their own little PvP battles on a 3rd party site (setting up a tournament would be an interesting proof of concept). If it ever got traction and had a lot of players I'm sure the guys would look at it, but I just can't see it being mass appeal to the users. 

I just wanna play chess, but no I guess it wouldn't really implement well here. 

Well they would most likely have to code the game themselves as taking the code from someone/someplace else wouldn't be ethical. I've coded a chess game before and it is quite a bit of work as you have to code each piece with the moves they would be allowed to take, checkers would be much easier but still quite a lot of lines of code. I'm sure you could find a PvP chess game online somewhere and just place your bets and play the game and the loser sends the money afterwords. If you don't trust the person you are playing with to send you money after they lose have a third party hold the bets while the game is going and/or get proof of the bet so if they don't follow through you shoot them in the face. 

chess would be nice i like the idea

SIR KEYPUNCH AGREES WITH CHESS!

I'd love to play chess! Could wager money, I think it'd be a great addition to the game

Why not Chess-Boxin?

Chess Seems like a fun game

Chess-boxing will be an Ace.Whoever loses a chess piece takes a punch in the nose.