Much like in Diablo and Diablo II, the quality and attributes of equipment are randomized. In addition to base stats (such as damage and attack speed for weapon or armor points on armor) higher-quality items have additional properties such as extra damage, attribute bonuses, bonuses to critical hit chance, or sockets, which allow items to be upgraded and customized by adding gems for various stat bonuses. Magic-quality items have up to three random properties, rare-quality items have up to six, and legendary-quality items typically have up to eight with varying degrees of randomness. Set items are a subtype of legendary items which provide additional, cumulative bonuses if multiple items from the same set are simultaneously equipped. Higher level monsters tend to drop higher level items, which tend to have higher base stats and bonuses.