Out of 13 cruises, we've taken liquour on board 12 times with no problem. DH packs a litre of scotch and I take a litre of vodka. We buy PLASTIC bottles, put it in a plastic bag and pack it in the center of our checked luggage. We set up our own small bar in the cabin in plain view. I think as long as you don't get too greedy you won't have a problem. We do buy some drinks on board but enjoy a drink in our cabin pre-dinner. We've also bought booze in St. Thomas and St.Maarten and brought it back on board wrapped in a beach towel in a beach bag. That said, we don't fly so we're not contending with airport handlers or security-just the cruise lines. Also, the port of embarkation might make a difference-some countries might have tighter regulations.