Go and register the kids on the first day Adventure Ocean open house. In pastimes, the kids club had lanyards and will punch a hole in their cards so the kids can wear them. Not sure if they still have lanyards as my kids have outgrown the club. If you are on a newer ship, you can buy them WOW bands which would let them into the rooms but I don't think they can be used in the arcade; I believe you have to swipe your card there. And yes - I found out the hard way - that kids can spend way more then they should in the arcade.