"Nothing in life is free." It's a phrase my husband has said over and over again. It's right there on his list of best phrases with "Life isn't fair." The kids really hated that second one. So is anything on a cruise ship "free?" Perhaps the better question to ask is "What's included?"
Depending upon the cruise line you may have everything included, or most everything, or as we have found in some cases, many things are ala carte. I know as kids we hated homework but this is one time when you really do need to do it. Thanks to the internet cruise line sites and lots of forums that are available you can usually get a good idea of what to expect.
Most cruise lines today include the gratuities for your dining room staff, stateroom, and various other positions on board ship that you may not even realize get a tip. You can always add to it if you like and if you've gotten really bad service (it would be very unusual) you can ask to not have the gratuity given to that staff member. I suspect the reason gratuities are included is because too many people neglected to give any gratuities when it was not included in your cruise fare. Beverage servers however still seem to garner a 10% gratuity for each drink they bring you unless you are on a cruise where drinks are included in your fare.
Usually the more expensive smaller cruise lines are the ones who have an all inclusive price. While the price might be higher, it often includes (in addition to gratuities) all of your drinks, one or more nights at a specialty restaurant on board and in some cases excursions in ports.
Of course you can also get your airfare included with most cruise fares and that normally includes transportation from the airport to the ship. It pays to check out the cost of booking that yourself but remember that if the air booking cuts it too close to the ship's departure, it could leave without you. Usually if air passengers who booked through the cruise line have some problem caused by the airline which makes them a little late the ship will wait. We waited once on a plane full of German cruisers that arrived an hour late in Miami.
The one constant with cruise lines as it is with most anything in life is that things will change. Again, we're back to doing that homework. If it's been a while since you've cruised with a particular line be sure to check on just exactly what your cruise fare includes. Earn that A+!