No we aren't talking about a place to live, these are virtual game lobbies or rooms as we call them. And each room has it's own number, just like a hotel would have room numbers on the doors.

You can find a suitable room, from one of these sites.

• Monster Game Steam Group
  
• xPaw TowerAttack[lab.xpaw.me]

This is a very important step, you really have to make sure you are on the correct page for this to work, if you are on the wrong page you will get an error.

• The correct URL you should be on is: http://steamproxy.com/minigame/
  
  

• From the menu: select "More Tools", and then "JavaScript console"

Alternatively you can use a key combination.

• Press Ctrl+Shift+J on your keyboard.

• from the menu: select "Browser Console" from the Web Developer submenu in the Firefox Menu (or Tools menu if you display the menu bar or are on OS X)

Alternatively you can use a key combination.

• Press Ctrl+Shift+J (or Cmd+Shift+J on a Mac) on your keyboard.

When you have the console open, you can paste or type the following command.
Replace the x with your room number.

• JoinGame(x);

• There was a problem trying to join a game. Please try again later.
  • The room is not online yet, or it's full, try again!
  
  
• The HTTP Error code 400 "Bad Request"
  • The room is not online yet, or it's full, try again!
  
  
• Uncaught ReferenceError: JoinGame is not defined
  • Refresh, or read the guide again.