Activision has faced complaints from Major League Baseball. MLB has opposed Activision's use of the phrase "World Series" in the name of a Call of Duty esports tournament.
Representatives of the MLB governing body filed an objection with the United States Patent and Trademark Office (USPTO) against Activision's attempt to secure the trademark "World Series of Warzone" (such events have been held since 2021).
Activision responded and on the same day sent a notice to the regulator of a voluntary abandonment of the trademark registration.
Trademark registration applications can be challenged publicly within a specified period. For "World Series of Warzone," this period began in the summer of 2025. Last year, MLB representatives already indicated to the Patent Office that they might object to the registration of Activision's trademark.
In its complaint, MLB noted that the name World Series of Warzone "is likely to cause confusion" with their own trademarks — such as World Series, College World Series, and World Series 2000.
MLB representatives emphasized the longevity and recognition of the "World Series" brand, which has been used for over a century to denote "iconic and most anticipated baseball events in the world."
MLB also expressed dissatisfaction with the word "zone:":
The word “zone” is frequently used to identify particular zones, sectors, or areas associated with league events,” and “strike zone” is the area through which a ball must pass to count as a strike.
