answer-with-invalidity-contentions

name	answer-with-invalidity-contentions
title	Answer with Invalidity Contentions
description	Drafts a defendant's Answer with Invalidity Contentions responding to a U.S. patent infringement complaint. Covers FRCP 8(b) admissions/denials, affirmative defenses, and PLR 3-3 invalidity contentions with claim charts under 35 U.S.C. §§ 101, 102, 103, 112. Use when representing a defendant in the pleadings phase of federal patent litigation who must respond to an infringement suit and assert prior art, anticipation, obviousness, or § 112 defenses.
author	CaseMark
author_url	https://github.com/CaseMark/skills/tree/main/skills/legal/answer-with-invalidity-contentions
license	Apache-2.0
version	0.1.0
execution_mode	open
jurisdiction	us
practice	ip
language	en
tags	["drafting","litigation","pleading"]

Answer with Invalidity Contentions

Combined answer and Patent Local Rule 3-3 invalidity contentions for a patent defendant — responds to each complaint allegation while building the invalidity record for trial.

Prerequisites

1. Complaint — all numbered paragraphs requiring response
2. Asserted patent(s) — specification, claims, and prosecution history
3. Prior art — patents, publications, products, or public uses with qualifying dates
4. Jurisdiction — district court and applicable local patent rules (PLR 3-3 or equivalent)
5. Effective filing date — pre-AIA (before March 16, 2013) vs. AIA § 102 framework
6. Accused product/method — for non-infringement admissions and denials

Output Structure

1. Caption and Introduction

• Full party names, civil action number, division
• Title: DEFENDANT'S ANSWER AND INVALIDITY CONTENTIONS
• Jury demand if not previously filed (FRCP 38)
• Opening denial of infringement of any valid, enforceable claim

2. Admissions and Denials (FRCP 8(b))

Respond paragraph-by-paragraph mirroring complaint numbering.

Response	When	Language
Admit	Verifiable facts (jurisdiction, patent issuance)	"Defendant admits U.S. Patent No. X was issued on [date]."
Admit in part / Deny in part	Mixed fact and legal conclusion	"Admits it manufactures [product]; denies infringement of any valid claim."
Lack of knowledge (8(b)(5))	Within plaintiff's peculiar knowledge	"Lacks sufficient knowledge; treated as denial."
Deny	False facts and all legal conclusions	"Defendant denies."

• Address each sub-part of compound paragraphs individually
• Close: "All allegations not expressly admitted are denied." (FRCP 8(b)(6))

3. Affirmative Defenses

Number separately. Apply Twombly/Iqbal plausibility with brief factual predicates.

#	Defense	Notes
1	Non-infringement	Literal and DOE
2