Birth to a Luxembourgish parent creates Luxembourgish nationality. Birth in Luxembourg alone to two foreign parents is not unrestricted jus soli.
Sources: Luxembourg Guichet - naturalisation
Option by marriage: a resident spouse of a Luxembourger has no minimum residence or marriage-duration requirement (language and integration course only).
Sources: Luxembourg Guichet - naturalisation
A child of a Luxembourgish parent is Luxembourgish under the nationality law. Option and reclamation routes cover additional family and historical cases.
Sources: Luxembourg Guichet - naturalisation
Adults with five years legal residence (final year uninterrupted), Luxembourgish language certificate, and the Living Together course or exam may apply. Good repute rules apply. Dual nationality is generally allowed.
Sources: Luxembourg Guichet - naturalisation