When purchasing liquor on the duty-free islands that are known for their liquor deals, yes your case of liquor will be taken from you when you board. There is a desk right next to the scanner where they will take your liquor- they have a manifest that they fill out- how many and what type of liquor you bought, your name and cabin number. Your liquor will be delivered to your cabin on the last night of the cruise. I suppose that if you only had one small bottle of liquor and you wanted to have a drink in your cabin, you could try to hide it in your carry-on wrapped in a towel or something and hope that security didn't decide to search your bag. Wine and champagne are allowed to be brought back to your stateroom in moderate quantites.