Which popular video game franchise has released games with the subtitles World At War and Black Ops?

Call of Duty.

Explanation:

Call of Duty was first published on the 29th of October, 2003 by Activision. Call of duty refers to a popular first-person shooter video game franchise focused on developing games that are related to the World War II, Cold War, space, new and futuristic world series.

The software developers who designed and developed Call of Duty are Infinity ward, Raven software, Sledgehammer games and Treyarch.

In November 2008, Call of Duty: World at War was developed by Treyarch and released for Playstation 3, Xbox 360, Microsoft Windows, Nintendo DS, and Wii. Similarly, Call of Duty: Black Ops was released in November 2010 worldwide for different gaming platforms.

Hence, Call of Duty is a popular video game franchise that released games with the subtitles World At War and Black Ops. Also, Call of Duty can be played either by a single player or multi-players.