Gems let heroes to get additional bonuses for Damage and Health.

Every hero has several slots for the Gems. (The slots are different from the slots for equipment).

The number of slots depends on the hero rarity:

Common — no slots

Special — 1 slot

Rare — 2 slots

Legendary — 3 slots

Epic — 3 slots

Power of gems (by rarity):

Common — 5%

Special — 10%

Rare — 15%

Legendary — 20%

Epic — 25%

How to create a gem of a higher rarity.

You can merge gems of a lower rarities to get a gem of a higher rarity. To merge the gems you need to pay a price in gold. The higher the rarity, the higher the price.

The gems which are already used in the slots of heroes can’t be used for the merging. You need to take them off before any operations.

Books.

Every Epic hero can equip one book. The Books can add heroes one additional passive ability.

The power of the ability depends on the rarity of a book (from Common to Epic).

Hero can equip only a book with an ability that he doesn't have himself.

The book can be equipped only into an empty slot. To make the slot with a book empty again you can destroy a book or take it out.

The cost of destruction is in silver, the cost of the take out is in gold.

Types of books: