How do badges work?

Badges are achievement awards available in certain games. 

Some badges can be earned through gameplay such as the social gamer badge which will reward you for reaching level 5, and, other badges, like gems, are unlocked by making in-app purchases.

To determine whether a game offers badges, click the game and look for a section titled "Badges" in the game information section. 

If you notice that a game doesn't include any mention of badges in this section, it is because the game does not offer badges.