Conducting a 'knighting' ceremony with one's erect penis. Tapping it on the right and left shoulder of your subject will give them the Royal Advantage.
Alternatively, a woman can conduct this ceremony using a strap-on dildo.

Once the ceremony is complete, one has the Royal Advantage.
Olive: How'd last night go?
Dirk: I now have the Royal Advantage.
by How It Sir February 2, 2018
Get the Royal Advantage mug.