Under Penal Law §210.00, an "oath required by law" refers to:

Detailed Explanation

This definition matters for perjury questions involving sworn writings. Penal Law §210.00(4) says an affidavit, deposition, or other subscribed written instrument is one for which an oath is required by law when, without the oath, it would lack legal efficacy before a court, governmental body, agency, or public servant. Not to be confused with testimony, which is separately defined in §210.00(3).