Yes, there is typically a fee to participate in the escape room, known as The Observatorium, on Royal Caribbean's Mariner of the Seas. As of 2026, passengers can expect to pay approximately $20 to $35 per person for this high-value, immersive experience. The game is located in the ship's former chapel area and utilizes advanced technology and mechanical puzzles to challenge groups. It is a peer-recommended "must-do" for fans of logic and teamwork, though it is important to note that sessions are often not private; you may be paired with other cruisers to fill the room's capacity (usually around 12 people). Because it is a popular activity with limited time slots, it is a high-value strategy to book your session through the Royal Caribbean app or at the Guest Services desk as soon as you board. While some on-ship activities are included in your fare, the high production quality and limited throughput of The Observatorium make it one of the "premium" upcharge experiences.