Delaware District Judge Richard G. Andrews has whittled down the issues remaining in a lawsuit filed by Acceleration Bay, LLC against Activision Blizzard—ruling that one of its infringement theories is barred due to collateral estoppel, which prevents a party from relitigating an issue already fully decided in a prior case. While Judge Andrews declined to find that an earlier summary judgment ruling for Take-Two Interactive collaterally estopped the plaintiff’s literal infringement claims, he determined that the prior decision did preclude Acceleration Bay’s theory of infringement under the doctrine of equivalents (DOE)—concluding that it had repeated an “especially weak” argument from before. The holding is not the first setback experienced by the inventor-controlled plaintiff in this long-running campaign, which has been litigated with the backing of a third-party funder—among them an early 2020 ruling by Judge Andrews that undercut its damages case on the eve of a previously scheduled trial.