Non-class skill books are expert skill books which any class can use. Although, unlike ordinary expert skill books, these skill books can not be upgraded. Most of them grant only small improvements but few of them are actually quite powerful. At the moment, there are 33 non-class skill books, 31 of which are passive and two that are active. Only requirements to use these books are character level 18 and empty expert skill slot. These books can be obtained by killing raid bosses, participating in