Gems can be inserted into the equipment, significantly increasing its combat power and granting additional stat bonuses. An inlaid gem is bound to the equipment slot and not to any particular item, so the gem stats won’t be lost if the character replaces their gear.
Inlaying a certain number of gems of particular level will grant an additional stats bonus.
The level and number of gems needed to activate the bonus depends on the level and quality of the equipment. Note that with some slots only gems of a certain color can be inlaid. Red, blue and yellow gems can be bought from the Silver Shop, found by using treasure maps, caught while fishing, and obtained during events. Colorful gems can be purchased at the Auction House for gold, found with treasure maps, or won as a reward for placing in the Arena leaderboards.