If you ask a non-Jew to do a prohibited Melacha for you on Shabbat: if he is a Ger Toshav it is a Torah prohibition; if a regular non Jew – a rabbinic prohibition. (Yevamot 48b; Rashba)
Ger Toshav will only be accepted as such, when Yovel we be practiced. (Rambam ibid)
