The Reward book is a book given to a player after he or she has defended the gatehouse in the Troll Invasiondistraction and diversion and to the players who participated in the test tutorial in the Combat Beta. The player has the option of choosing which skill they wish to gain experience on. When a player tries to play the activity again without having used the Reward books experience or destroyed the book, Captain Jute states, "Sorry, lad/lass. I can't let you defend us from the troll hordes until you've used up your reward from last time. Can't have these things piling up, you see."
The reward book can be banked, unlike many other experience-giving items.
The book will give experience based on your skill level when it is used, not when it was earned.
The amount of experience received from the reward book is
where is the level of the skill on which it is being used, is the wave completed (or trolls killed in defending) and is the total number of waves (20 on easy, 7 on hard, 1500 in defend). Note that for Invention, any experience received is halved.