var Game = function(){
    var game = this;
    game.Player = {
        pts:[]
    }
   }
for example in php it could be as:
game.Computer extends game.Player
But how can I do a child from game.Player in javascript in the same class?
[update] [1]
var Game = function(){
    var game = this;
    game.Player = {
        pts:[],
        test: function(){ alert('test'); }
    }
    Player.prototype = new Computer;
    game.Computer = {
    }
}
var game = new Game();
game.Computer.test();
I'm not sure @BenM
[update] [2]
or even like this:
var Game = function(){
    var game = this;
    game.Player = {
        pts:[],
        test: function(){ alert('test'); }
    }
    game.Player.prototype = game.Computer {
    }
}
var game = new Game();
game.Computer.test();
That is wrong too, can't extend it as is. Sorry if it's a lot of code here.
 
    