Litigation summary

Known Litigation Involving US Patent 8,641,525

As of May 9, 2026, US Patent 8,641,525 has been the subject of significant litigation, most notably involving Valve Corporation and Collective Minds Gaming Co. Ltd. Below is a summary of the known legal proceedings.

Ironburg Inventions Ltd. v. Valve Corporation

This has been a multifaceted legal battle spanning multiple jurisdictions, including district courts, the Patent Trial and Appeal Board (PTAB), and the Court of Appeals for the Federal Circuit (CAFC).

• Plaintiff: Ironburg Inventions Ltd.
• Defendant: Valve Corporation

1. District Court Litigation:

• Initial Filing:

  • Jurisdiction: U.S. District Court for the Northern District of Georgia.
  • Case Number: 1:15-cv-04219.
  • Filing Date: December 3, 2015.

• Transfer and Trial:

  • The case was later transferred to the U.S. District Court for the Western District of Washington.
  • Jurisdiction: U.S. District Court for the Western District of Washington.
  • Case Number: 2:17-cv-01182.
  • Outcome: On February 1, 2021, a jury found that Valve willfully infringed claims of US Patent 8,641,525 and awarded Ironburg over $4 million in damages. The trial was notably conducted virtually via Zoom. Post-trial motions by Valve for judgment as a matter of law or a new trial were denied in May 2021. Ironburg's motion for enhanced damages was also denied.

2. Patent Trial and Appeal Board (PTAB) Proceedings:

• Case Number: IPR2016-00948.
• Filing: In response to the initial lawsuit, Valve filed an inter partes review (IPR) petition challenging the validity of the '525 patent. The PTAB partially instituted the IPR.
• Outcome: The PTAB found certain claims of the patent unpatentable, but other claims survived the review. This proceeding led to the issue of IPR estoppel, which limited the invalidity arguments Valve could raise in the district court trial.

3. Court of Appeals for the Federal Circuit (CAFC) Appeals:

The district court's decisions and the PTAB's findings have been the subject of appeals to the CAFC.

• Case Numbers: Including 21-2296 and 2022-1070.
• Status/Outcome: In an April 2023 decision, the Federal Circuit addressed the issue of IPR estoppel, affirming in part and vacating in part the district court's ruling. Specifically, the court found that Valve was estopped from raising invalidity grounds that were included in its IPR petition but on which the PTAB did not institute review. However, it vacated the district court's ruling regarding grounds that were not included in the IPR petition, remanding the case for further proceedings and clarifying the burden of proof for estoppel. This has opened the door for Valve to potentially have a new trial on certain invalidity defenses. The litigation has involved other patents in the same family, such as U.S. Patent Nos. 9,089,770, 9,289,688, and 9,352,229.

Ironburg Inventions Ltd. v. Collective Minds Gaming Co. Ltd.

• Plaintiff: Ironburg Inventions Ltd.
• Defendant: Collective Minds Gaming Co. Ltd.

1. District Court Litigation:

• Jurisdiction: U.S. District Court for the Northern District of Georgia.
• Case Number: 1:16-cv-04110.
• Filing Date: 2016.
• Status: The case involved a motion to stay pending inter partes review.

2. Patent Trial and Appeal Board (PTAB) Proceedings:

• Case Number: IPR2018-00354.
• Filing: In 2018, Collective Minds also filed an IPR petition challenging claims of the '525 patent.
• Outcome: This IPR was instituted by the PTAB; however, the parties reached a settlement before a final written decision was issued.