Also known as:legal defenses · legal defence · legal defences · defence
Written by attorneys · grounded in primary & secondary sources — see below
A defendant's stated reason why the plaintiff or prosecutor has no valid case. It encompasses answers, denials, pleas, and affirmative assertions of facts that defeat the claim even if all allegations in the complaint are true.
Sources & Authorities
How it applies
Common Examples
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Sixth Amendment Counsel Claim
After indictment on fraud charges, Warren's public defender failed to interview key witnesses before trial. Warren moved to suppress statements obtained without counsel and asserted his constitutional right to assistance as a complete bar to further proceedings. The court evaluated whether the absence of counsel at critical stages supplied a valid legal defense requiring reversal.
Congressional Defense Power
Congress enacted a statute imposing a messaging charge on streaming platforms that declined to air public-service announcements. Union Entertainment paid the charge but challenged it as exceeding enumerated powers. The company raised the constitutional allocation of defense and general-welfare authority as a legal defense to enforcement.
Select any source to read its text and confirm it supports the definition.
Federal Rules
Dictionaries
Indigent Defendant Counsel Right
Gideon was charged with a felony and could not afford counsel. He requested appointed representation at trial but was denied. Gideon raised the absence of counsel as a legal defense on appeal, arguing the conviction could not stand without it.
Gideon v. Wainwright372 U.S. 335 (1963)
University Funding Speech Claim
Student editors at a public university were denied funding for a religious publication under school policy. They sued, asserting that the denial violated free-speech protections. The university raised its funding criteria as a legal defense to the constitutional claim.
Rosenberger v. Rector and Visitors of the University of Virginia515 U.S. 819 (1995)
Ineffective Counsel Challenge
Washington was sentenced to death after his lawyer failed to present mitigating evidence during the penalty phase. He collaterally attacked the sentence, claiming counsel's omissions constituted a legal defense that undermined confidence in the outcome.
Strickland v. Washington466 U.S. 668 (1984)
Privacy Statute Challenge
Texas prosecuted Lawrence under a statute criminalizing private consensual conduct. Lawrence raised substantive due-process protections as a legal defense, arguing the statute could not constitutionally reach the conduct at issue.
Lawrence v. Texas539 U.S. 558 (2003)
Common questions
Frequently Asked
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Who bears the burden of proving an affirmative defense such as privilege in a defamation action?+
The defendant asserting the defense must prove the facts necessary to establish that a qualifying privilege applied. The plaintiff need not disprove the privilege as part of the prima facie case.
Does a defendant's mental impairment provide a legal defense to a negligence claim?+
No. Adults are held to an objective reasonable-person standard regardless of cognitive decline or mental illness. The impairment does not excuse failure to meet that standard or shift loss to innocent victims.
When may a court order production of materials containing attorney work product?+
Factual work product may be ordered produced upon a showing of substantial need and undue hardship, but opinion work product reflecting mental impressions and legal theories receives heightened protection and ordinarily remains shielded.
What must lawyer advertising include to avoid discipline?+
Every communication about legal services must identify by name at least one lawyer or law firm responsible for its content and supply contact information for that lawyer or firm.
41 U.S. 1 (1842)Conflict of Laws
…in New York, instituted by the holder, a citizen of Maine. The acceptance and indorsement of the bill were admitted. The defence was rested on allegations that the bill had been received in payment of a pre-existing debt; that the acceptance had been given for lands which the acceptor had purchased from the drawer of…