Guides · Patent Litigation
Summary Judgment, Experts, and Daubert
After claim construction and expert reports, many patent cases are narrowed or decided on summary judgment.
· Law checked through October 20, 2026
In Short
After claim construction and expert reports, many patent cases are narrowed or decided on summary judgment. Patent cases are also contests between experts: technical experts on infringement and validity, and economists on damages. Judges must screen expert testimony before it reaches the jury, and in 2025 the Federal Circuit, sitting en banc, stressed that this duty applies with full force to damages experts.
Common situations.
- After the claim construction ruling, a defendant believes its product cannot infringe as a matter of law.
- A damages expert relies on licenses that do not say what the expert says they say.
- A technical expert applies a meaning of a claim term that the court rejected.
Summary judgment.
A court grants summary judgment when there is no genuine dispute of material fact and the movant is entitled to judgment as a matter of law (Fed. R. Civ. P. 56(a); Celotex Corp. v. Catrett, 477 U.S. 317 (1986)). The court views the evidence through the lens of the burden that would apply at trial (Anderson v. Liberty Lobby, Inc., 477 U.S. 242 (1986)).
| Motion | Who usually files | Notes |
|---|---|---|
| Noninfringement | Accused infringer | Often follows a favorable claim construction; must show no reasonable jury could find each element met |
| Invalidity | Accused infringer | Harder, because invalidity requires clear and convincing evidence; § 101 and indefiniteness are legal questions well suited to early resolution |
| No willfulness or no pre-suit damages | Accused infringer | Common where there was no notice or marking |
| Validity or infringement | Patent owner | Less common; may target defenses lacking evidence, such as inequitable conduct |
| Equitable defenses | Either | Estoppel and similar defenses are decided by the judge |
Experts in patent cases.
- Technical experts explain the technology and testify on infringement or invalidity, element by element. They must apply the court's claim construction; testimony based on a different construction can be excluded.
- Damages experts testify on lost profits or a reasonable royalty. Their methods include analyzing comparable licenses, estimating the value of the patented feature, and modeling a hypothetical negotiation. See Remedies.
- Other experts may address surveys, industry practice, or Patent Office procedure. Experts on patent law itself are generally not permitted to tell the jury what the law is.
The judge as gatekeeper.
A qualified expert may testify only if the proponent shows it is more likely than not that the testimony will help the jury, rests on sufficient facts or data, uses reliable methods, and applies those methods reliably to the case (Fed. R. Evid. 702, as amended Dec. 1, 2023; Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579 (1993)).
In EcoFactor, Inc. v. Google LLC, No. 2023-1101 (Fed. Cir. May 21, 2025) (en banc), the Federal Circuit held 8-2 that a trial court abused its discretion by admitting a damages expert's opinion that three earlier licensees had agreed to a particular per-unit royalty, when the licenses themselves did not support that premise. Whether an opinion rests on sufficient facts is a gatekeeping question for the judge, not a matter of weight for the jury. The court ordered a new trial on damages. Since EcoFactor, a damages opinion that relies on comparable licenses must be tied to what those licenses actually show.
Timing in Texas.
- Eastern District of Texas. Dispositive and expert motions are due on dates set in the docket control order, typically after expert discovery closes and a few months before trial.
- Western District of Texas. Under the Waco standing order (OGP 4.0), dispositive and Daubert motions were due about 40 weeks after the claim construction hearing. Confirm the assigned judge's current schedule.
- Pretrial. Motions in limine, which ask the court to keep specific evidence or argument from the jury, are decided at or near the final pretrial conference and often shape what each side can say about licenses, Patent Office proceedings, and the parties' size.
Sources.
- Fed. R. Civ. P. 56.
- Fed. R. Evid. 702 (as amended Dec. 1, 2023).
- Celotex Corp. v. Catrett, 477 U.S. 317 (1986).
- Anderson v. Liberty Lobby, Inc., 477 U.S. 242 (1986).
- Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579 (1993).
- EcoFactor, Inc. v. Google LLC, No. 2023-1101 (Fed. Cir. May 21, 2025) (en banc).
- W.D. Tex. Standing Order Governing Proceedings (OGP) 4.0, Patent Cases (Mar. 7, 2022).
This guide is general information, not legal advice. Law checked through October 20, 2026. See the Disclaimer.