Leveling Up

Level Cap

The level cap is 20. You no longer gain exp once at level 20. The level cap increases by 5 for every time the character beats the game and goes into New Game plus (aka NG+).
Level cap = 20 + CharacterNG+ * 5

You can check your character's level cap by hovering over the EXP tracker in your character menu.

Skill and Attribute Stars

You gain 3 Skill and Attribute stars for each level your character gains. You can get bonus stars from guild hall accomplishments.
You can be spent at the Training Grounds to upgrade your skills, the Enchanter to attune items whose blueprints you've found, or the Weapon Mastery to attune different types of weapon types for increased damage.