In Acceleration Bay, LLC v. Activision Blizzard Inc., the Federal Circuit affirmed the PTAB’s holding that certain claims of patents owned by Acceleration Bay were unpatentable in view of prior art. The Federal Circuit confirmed the Board’s finding that two claim terms, “game environment” and “information delivery service,” were not substantive limitations of the claims afforded patentable weight. Because both claim terms appear in claims that do not have a transition phrase formally denoting a preamble, Acceleration Bay argued that the terms are not a part of the claims’ preambles, and therefore, are necessarily part of the body of the claims and limiting in nature. The Court rejected this argument, instead finding that the two terms both appear in the preambles of their respective claims, despite lack of transition phrases. It further cautioned patentees to avoid such “poor claim drafting” by including a transition word to clearly delineate between the preamble and the body. Having determined that the terms each appear in the preamble, the Court agreed with the Board’s determination that the terms are non-limiting because they merely describe intended uses for an otherwise complete invention.