Actually the only way to get them now is through the Narnia Adventure game or if someone has a code for a set bc they are not tradeable. I sent you a PM with a code. I had 2 left from a long time ago.
Nobody seems to have answered your basic question here. Randomly (rumored to be once in every 5000 total game plays) you will get the code popup box immediately after you click "Play" at the very beginning of the game.
I was just checking some threads I had posted in and saw this. I apologize also Mal. I didn't realize you were not allowed to gift items from the online games. I thought you just were not allowed to trade them for something in return. Does this apply to all items that can be won by playing the online games like POTC Dead Man's Chest Codes, the Galleon ship codes, Terabithia tree houses, Nemo subs? I have seen threads of ppl offering these codes for those that cannot play or their computers can't handle the games. Again I am sorry I didn't know it wasn't allowed and ty for setting me straight on this.