Firaxis Games is a studio that's best known for its work on strategy games, including XCOM, Civilization, and Marvel's Midnight Suns. 

The studio was founded in 1996 by Sid Meier, Jeff Briggs, and Brian Reynolds. Meier himself is such a household name that his name appears on many video games. 

While the studio has stayed within the strategy genre, it has experimented with different styles and approaches. 

Marvel's Midnight Suns blends turn-based strategy with a card game, XCOM focuses on tactical, cover-based conflicts, and Civilization is a 4X, which is an abbreviation of Explore, Expand, Exploit, Exterminate. Should be 4E, really, eh?