Fame is the currency besides Realm Gold, but unlike Realm Gold, Fame can only be achieved by playing the game itself (You have to die to get it). fame can be spent on feeding pets, fusing pets
Fame can be gathered from defeating monsters. The harder the monsters you fight, the faster you gain fame.
At first, you won't be able to keep track of how much fame you earn. After you reach level 20 (the maximum level), you will see an orange bar replace the green one that shows your experience. This bar shows how much fame you have when you mouse over it, and will fill as gain fame for the particular character you're playing as.
If you complete enough class quests (completed by gaining a certain amount of fame for a character). Your "Star" will change color. This star shows how much class quests you have completed. You start off with a pale blue star. The highest level star is the white star. Your star is shown beside your name on the main screen.
But with recent updates to the game fame can no longer be used for keys to dungeons only for fusing or feeding pets which is a real disappointment