When Prince George turns 12 on July 22, he’ll be met with a significant shift in royal tradition. As the future heir to the British throne, George will no longer be allowed to travel on the same plane as his father, Prince William.

This long-standing rule is in place to safeguard the line of succession, minimizing the risk of losing multiple heirs in the event of an accident. The same travel restriction may eventually apply to Princess Charlotte and Prince Louis as well, depending on their positions in the royal succession.

At present, Prince George is second in line to the throne, following Prince William. His younger siblings, 10-year-old Charlotte and 7-year-old Louis, follow him in the order of succession.

Unusual Rules the Royal Children Must Follow

Growing up in the royal family comes with a unique set of guidelines—and George, Charlotte, and Louis are no exception.

No Monopoly at Home
According to The Telegraph, Monopoly is off-limits in the royal household. Back in 2008, Prince Andrew revealed, “We’re not allowed to play Monopoly at home. It gets too vicious.”