|“|| Magical items can help your hero to get better statistics and unlock some new special attacks. You can craft them when you click on the Throne building of your hero.
Each item can be categorized in one of five rarity types: Common, Uncommon, Rare, Legendary and Special. Better the rarity, bigger boost to statistics it gives.
There are two kinds of crafting options you can use:
Basic crafting: Using Nectar you can craft items from Common to Legendary. The higher level of the hero you craft the items for, the more expensive the craft is. Hit the crafting window with the hammer, to reveal what item you got for your hero. Of course, the more powerful item, smaller the chance to get it.
Master crafting: Using Gems you can craft more powerful items for your hero. From Uncommon rarity to the most powerful special items, that not only gives you stats boost, but when collecting the whole set of them, the new special attack unlocks for your hero, depending on the set. Each week the featured sets change.
— Game's Help Pages