* "Football game" as a general concept: If you're talking about the general idea of a football match, then it's a common noun.
* Example: "I love watching football games on TV."
* "Football game" referring to a specific event: If you're referring to a specific football game, like the Super Bowl or a game between two teams, then it's a proper noun and should be capitalized.
* Example: "The Super Bowl is the most watched football game in the United States."
Let me know if you want to look at another example!