The policy at most all inclusive resorts is that price includes gratuities, but practices vary in real life. Some places strictly forbid tipping, while at others (especially in Mexico) tipping is expected. Read comments at a site like TripAdvisor.com for particular properties. Bring dollar bills; $100 could be enough for a week. (See more about Tipping.)
Pools: Heated or Not?
Resort swimming pools -- plus their waterfalls, waterslides, etc.-- are often more popular than the beach. Note, however, that most pools in Mexico and the Caribbean aren't heated except by the sun; if the weather gets cool, the pools do too. Newer properties are more likely to have heated pools.
Lounge Chairs at the Pool
This is perhaps the most frequent complaint by visitors: a resort doesn't have enough lounge chairs at the pool or beach and guests feel forced to get up early in the morning to throw a towel over an empty chair and claim it for the day. Other guests then resent the fact that lounge chairs sit empty but can't be used because someone's claimed them with a towel.
What to do? Read visitor comments and perhaps you'll find a resort that either provides ample lounge chairs (even at peak times of the year) or else doesn't allow lounge chairs to be staked out.
This practice seems to be dying out, but some beach resorts have strict policies about pool towels. For example, guests may be issued a card that they exchange for a pool towel; they're expected to reclaim that card and turn it at the desk when they check out. Again, TripAdvisor.com comments will have the details about a particular resort. If you feel that hassles for lounge chairs or pool towels will annoy you, try another place!
Limited Dining at A La Carte Restaurants
Most resorts offer buffet plus several specialty restaurants. Visitors may find that they're limited to a certain number of meals at the a la carte restaurants; they may also find that reservations must be made early. Some guests complain about getting up early in the morning to make an evening reservation; others warn that dinner reservations should be made practically on arrival at the property.
Time-share sellers: can be aggressive at many properties, in Mexico and the Caribbean. Be firm with your "no".
Families with older teens: note that in Mexico, drinking age is 18, and at an all inclusive beach resort, your kids will get "adult" wristbands which means unlimited access to alcoholic drinks.
Day-Trips: take the opportunity to explore the country you're visiting. All resorts offer excursions, but if your eye's on the budget, you can probably find much less expensive DIY alternatives, especially if you choose a resort that's not in an isolated location.
Many beach resorts on the Mediterranean offer AI pricing, and are very popular with European families. Club Med resorts in particular are known for great kids' programs; Club Med also offers winter getaways in the Alps with included ski and snowboarding classes. Families can also choose nearly-all-inclusive cruises and "family adventure" escorted tours in Europe. Read more about All Inclusive Vacations in Europe.
Typically, family cruises provide meals, kids programs, entertainment. Families should budget extra for sodas, alcoholic beverages, shore excursions, and gratuities; also, if you have a baby and take a Disney cruise, you'll need to pay extra for baby care in Flounder's Nursery.
Our About.com Guide for Cruises notes: " In an effort to keep the basic price low, most mainstream cruise lines charge for everything that could be considered "extra", from wine to bottled water.... However, the basic cruise fare still includes room, board, and the traditional cruise ship amenities such as a swimming pool and entertainment, so you can cruise and only have to pay for tips and drinks if you choose."
Dude ranches and guest ranches typically provide three meals a day, and perhaps an afternoon snack; at some, kids programs are provided too. Horse-riding may be included, but not necessarily: be sure to check. Expect to pay extra for alcoholic beverages and snacks and drinks outside of meal-times.