Book of knowledge

A Book of Knowledge is a reward for the Surprise Exam! random event. It gives you experience (formula is stat lvl x 15) for example, with a prayer level of 60 you will receive 900 experience, making this random event better then other experience giving events. Compared with a genie lamp, which only gives the experience equal to the level times 10, making the book of knowledge much more useful.

If you try to bank it, you will receive the message "A magical force prevents you from banking this item!"

If a player still has a Book of Knowledge in their inventory and they get this random event again, a different reward will be given, such as an uncut emerald or uncut sapphire.

History
The Book of knowledge is presented as the tome of experience, since a player has proved his or herself capable of solving the multiple questions presented by the dragon Mr. Mordaut.