Yes, "Kids Sail Free" is a legitimate and popular recurring promotion by Royal Caribbean, but it comes with several specific terms and conditions. The offer generally applies to children aged 12 and under who are booked as the third or fourth guests in the same stateroom as two full-fare paying adults. While the "cruise fare" for the child is reduced to $0, parents must still pay for the child's taxes, fees, and port expenses, which can range from $100 to $250 per person depending on the itinerary. Furthermore, the promotion is usually subject to significant blackout dates, typically excluding high-demand periods like Spring Break (March/April), Summer (June–August), Thanksgiving, and Christmas/New Year's sailings. In 2026, many "Kids Sail Free" windows are specifically targeted toward the shoulder seasons or mid-week departures. To find these deals, travelers should look for the "Kids Sail Free" banner on the Royal Caribbean website during major booking holidays. It remains one of the best ways for families to significantly reduce the cost of a luxury vacation, provided they have the flexibility to travel outside of standard school holiday weeks.