Yes, ROYALTY is a Scrabble word!

Letter values in Scrabble US: R 1, O 1, Y 4, A 1, L 1, T 1, Y 4.

Is it a valid word?

ROYALTY is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

payment to the holder of a patent or copyright or resource for the right to use their property
royal persons collectively

Also: royal family, royal line, royal house.