To level up the current class, sufficient experience is required. Experience is gained from various tasks, such as killing monsters, doing quests, or various minigames.
Experience Penalty[]
When gaining experience from killing monsters, there is a penalty if the given monster is too low of a level compared to your own. If the monster is 6 levels below or higher, full experience is gained. Every level less reduces exp gain by 10%, so anything worse than 15 levels below gives no experience.
Level difference
EXP
+1 Or more
100%
± 0
100%
-1 to -6
100%
-7
90%
-8
80%
-9
70%
-10
60%
-11
50%
-12
40%
-13
30%
-14
20%
-15
10%
-16 Or less
0%
Experience Bonus[]
Experience bonuses can be aquired in various ways. One way is to check your daily fortune and if it is in your luck, you can get more experience points per monster. Another way is by various exp pills. You can get these pills through quests, gachas, or the Item Mall.