What do you have to pay for on cruise ships?

sizezeroasian asked:

I was just wondering if a cruise ship ticket covers the cost of everything on the cruise or if you have to pay extra for some things. Like, food, shows, massages, entertainment, clubs, booze, ect. Also, what is the legal drinking and gambling age on a cruise, do you have to be a certain age to go to the dance clubs on a cruise? If so what age? Thanks for your help!
Thanks for all the help so far! what about clubbing age on a cruse? 18, 21?