Birth to a Liechtenstein parent creates Liechtenstein citizenship. Birth in Liechtenstein alone to two foreign parents is not general jus soli.
Sources: Liechtenstein National Administration - naturalization
Facilitated naturalization for a spouse: post-marriage years count double, so about five years of residence instead of thirty.
Sources: Liechtenstein National Administration - naturalization
A child of a Liechtenstein citizen parent is Liechtenstein under nationality law, subject to registration rules for birth abroad.
Sources: Liechtenstein National Administration - naturalization
Ordinary naturalization is highly discretionary and typically involves about ten years residence plus municipal approval. Facilitated naturalization after about thirty years residence (years under twenty count double) or marriage routes also exist. Renunciation of prior nationality is required.
Sources: Liechtenstein National Administration - naturalization