The coat of arms at the entrance to Edinburgh Castle and motto "Nemo Me Impune Lacessit" is the motto of The Royal Regiment of Scotland which has its head quarters at Edinburgh Castle. The motto means literally, "Nobody assails me with impunity" or "Dinna mess wi' me ur else!"

"Nemo Me Impune Lacessit" was also the motto of The Royal Scots regiment, which was based at Edinburgh Castle from 1962 until 28 March 2006, until the six surviving Scottish regiments were merged into the Royal Regiment.