Local patent rules compared
Local patent rules are district-specific procedures that force both sides to commit to their positions early: the patentee serves infringement contentions with claim charts, the accused infringer answers with invalidity contentions, and the parties then exchange and brief disputed claim terms on a fixed sequence ending in a Markman hearing. The Northern District of California pioneered the model and the Eastern District of Texas adapted it; Delaware and the Western District of Texas reach similar results through default standards and judge-specific orders rather than formal patent rules.
What local patent rules do
The Federal Rules of Civil Procedure say little specifically about patent cases. Local patent rules fill the gap with three things the general rules lack:
- Early, binding contentions. The patentee must identify each asserted claim and each accused product and chart where every claim limitation is found. The accused infringer must identify its prior art and chart it against the claims. Theories not disclosed can be excluded.
- A claim construction sequence. The parties exchange terms, then proposed constructions and evidence, file a joint statement, take limited claim construction discovery, brief the disputes, and argue them at a Markman hearing.
- Limits on amendment. Contentions may be amended only with good cause or in narrow listed circumstances, which rewards diligence and discourages shifting theories.
The Federal Circuit has upheld this approach. In O2 Micro Int'l Ltd. v. Monolithic Power Sys., Inc., 467 F.3d 1355 (Fed. Cir. 2006), it approved the Northern District of California's requirement that a party show diligence to amend its contentions, describing the rules as designed to require parties to crystallize their theories early in the litigation.
District by district
Eastern District of Texas — Patent Rules ("P.R.")
Adopted in the mid-2000s and published as Appendix M to the court's Local Rules. Infringement contentions under P.R. 3-1 are due not later than ten days before the initial case management conference; invalidity contentions under P.R. 3-3 follow within forty-five days after service of the infringement contentions. Claim construction runs under P.R. 4-1 through 4-6. The court's Docket Control Order and Discovery Order set the actual dates, and a model order on focusing patent claims and prior art is often entered. Details: Eastern District of Texas patent rules.
Northern District of California — Patent Local Rules ("Patent L.R.")
The earliest of the modern local patent rules, first adopted around 2000 and amended several times since. Infringement contentions under Patent L.R. 3-1 are due fourteen days after the initial case management conference; invalidity contentions under Patent L.R. 3-3 follow forty-five days after service of the infringement contentions. Patent L.R. 4-3 limits the joint claim construction statement to the ten terms most significant to resolving the case, absent leave. The rules also provide for damages contentions. Details: Northern District of California Patent Local Rules.
District of Delaware — Default Standard and judges' orders
Delaware has no local patent rules. Instead, the court's Default Standard for Discovery, Including Discovery of Electronically Stored Information includes a section on initial discovery in patent litigation that requires a staged exchange: the plaintiff identifies the accused products and asserted patents; the defendant produces core technical documents for the accused products; the plaintiff serves initial claim charts; and the defendant serves initial invalidity contentions with the related prior art. The Default Standard also sets presumptive limits and procedures for electronically stored information. Each judge's form scheduling order then sets claim construction briefing (commonly a joint claim construction brief and chart) and the remaining case schedule. Details: District of Delaware.
Western District of Texas — judge-specific orders
The Western District has no district-wide patent rules. Patent cases are managed under standing orders issued by individual judges; the Order Governing Proceedings — Patent Cases used in the Waco Division became the best-known example, with an early Markman hearing and fact discovery opening after claim construction. Since a July 2022 order, new Waco patent cases have been randomly assigned among the district's judges, so the governing order depends on the judge drawn. Details: Western District of Texas.
Other districts
Many other districts have adopted local patent rules modeled on the California and Texas versions, including the Northern District of Illinois and the District of New Jersey. The structure is similar; the deadlines and the content requirements differ in detail.
What goes into contentions
Although the wording differs, infringement contentions under the California and Texas rules generally must include:
- each asserted claim, and the subsection of 35 U.S.C. § 271 under which each claim is asserted;
- each accused product, method, or other instrumentality, identified as specifically as possible;
- a chart showing where each limitation of each asserted claim is found in each accused instrumentality — the practical application of the all-elements rule;
- whether each limitation is alleged to be met literally or under the doctrine of equivalents;
- for indirect infringement, the direct infringement relied on and the acts of the accused inducer or contributory infringer;
- the priority date claimed for each asserted claim.
Invalidity contentions generally must identify each item of prior art, state whether it is said to anticipate or render obvious each claim (with the combinations relied on), chart where each limitation is found, and list any § 112 grounds such as indefiniteness, written description, or enablement. Both sides must also produce specified documents with their contentions.
Practical notes
- Always read the local rules together with the presiding judge's standing orders and the case-specific scheduling or docket control order; the case order usually controls the dates.
- Rules are amended periodically. Check the version currently posted on the court's official website before relying on a deadline described here or anywhere else.
- Contentions shape everything downstream: the terms that need construction, the scope of discovery, expert reports, and what can be argued at trial.
- Courts generally find good cause to amend only where the moving party acted diligently — for example, after an unexpected claim construction ruling or newly produced nonpublic technical information.
Frequently asked questions
What are local patent rules?
They are district-court rules that apply only to patent cases. They require early infringement and invalidity contentions with claim charts and set a fixed sequence for claim construction ending in a Markman hearing.
Does the District of Delaware have local patent rules?
No. Delaware relies on its Default Standard for Discovery, which requires a staged exchange of accused products, core technical documents, infringement claim charts, and invalidity contentions, together with each judge's scheduling order.
When are infringement contentions due in the Eastern District of Texas?
Under E.D. Tex. P.R. 3-1, infringement contentions are due not later than ten days before the initial case management conference, unless the court orders otherwise.
When are infringement contentions due in the Northern District of California?
Under N.D. Cal. Patent L.R. 3-1, infringement contentions are due fourteen days after the initial case management conference, unless the court orders otherwise.
Can contentions be amended later?
Generally only by court order on a timely showing of good cause, or in limited situations the rules list, such as after a claim construction ruling. The Federal Circuit upheld this diligence requirement in O2 Micro (2006).
See also
- Eastern District of Texas patent rulesP.R. 3-1 through 4-6, rule by rule.
- N.D. Cal. Patent Local RulesPatent L.R. 3-1 through 4-6, rule by rule.
- Patent discoveryProtective orders, source code, ESI, and contention practice.
- Markman hearingsThe claim construction hearing the rules lead up to.
- District of DelawareDefault Standard and judge-specific orders.
- Western District of TexasStanding orders and the 2022 assignment change.
Last reviewed: October 2026