In any action brought pursuant to sections 5B to 5O, inclusive, the party bringing the action shall be required to prove all essential elements of the cause of action, including damages, by a preponderance of the evidence.
Mass. Gen. Laws ch. 12, § 5L
Preponderance of the evidence standard
Official source: Massachusetts Legislature. Reproduced from public-domain Massachusetts statutes; confirm against the official source for the current text. Not legal advice.