What is the royal prerogative in the words of Dicey?
Dicey - "Every act which the executive government can lawfully do without the authority of an act of parliament".
Key phrase = 'executive government' as it means, they can do what they want to do without any need for parliamentary legislation.
The monarch can basically do everything the executive can.
Dicey states that the RP is a source of law that derives essentially from the common law.