A Book of war is a book held in place of a shield, and is the God book aligned with Bandos. It can be purchased from Jossik for 5,000 coins at the Lighthouse. Books of war must be made using all four torn Bandos pages which can be purchased from other players or obtained from treasure trails. Equipping a book of war allows the player to preach and perform ceremonies, such as blessing, last rites, and wedding rites, by operating it (none of which have any effect on the game itself, and are simply recited lines of text), costing 25% of the player's special attack energy.
Lost books of war can be reclaimed by speaking to Jossik, complete with all pages that have been added, for no cost. Alternatively, for those who do not wish to travel to the lighthouse, Perdu will return them to players for 12,000 coins
The book of war can be used as a training weapon for nightmare zone, as it offers a +5 prayer bonus and a +2 strength bonus. It is the only god book to give a strength bonus.
This book can be useful for melee training for low level players that don't have access to defenders or the obsidian shield yet.
Filling the Book of war currently costs 9,295 coins when buying each page individually or 19,748 when buying the item set.
The player may perform certain ceremonies by right-clicking the book and selecting "Preach." Preaching expends 25% of the special attack bar. The following are the options that appear when preaching and what the player says upon selecting them.
Big High War God want Great Warriors. Because you can make more... I bind you in Big High War God name.
You not worthy of Big High War God; you die too easy.
Big High War God make you strong... so you smash enemies.
War is best, Peace is for weak. If you not worthy of Big High War God, you get made dead soon.