$World = { 
  Players => [ 
   "player1" => { # each key is a player id
     ID=>"player1", HP=>9999, MP=>2000, coX=>0, coY=>0,
     Equip => [ qw/xxxSword yyyShield/ ],
     Magic => [ qw/Earthquake/ ],
     Invent => { Cure => 1, Poison => 3 } 
   },
   "playerx" => { ... } 
  ],
  Monsters=>{
    MonsterA => [ 
      "coX1-coY1", "coX2-coY2", ...
    ]
    MonsterB => [
      "coX1-coY1", "coX2-coY2", ...
    ]
  }
};