Zamorak's Book of Chaos

An Unholy book is a book held in place of a shield, and is the god book of Zamorak. For information on how to acquire a god book, see the god books article. Unholy books must be made using all four torn Zamorak pages which can be purchased from other players, obtained from treasure trails or by cremating a Vyrewatch. With an unholy book, a player can preach and perform ceremonies, such as blessing, last rites, and wedding rites by operating it. Also, if a player's Prayer level is 50 or higher, they can bless Unholy symbols with an Unholy book by expending 4 Prayer points for each symbol. When performing blessings, wedding ceremonies, last rites, or when preaching, 25% of the special attack bar is spent.

An Unholy Book is also very useful for Barrows because it gives good prayer and attack bonuses. It is also commonly used as a sidearm with a one handed ranging weapon such as a crossbow, as it provides the highest range attack bonus of any sidearm available. If you lose this item you can reclaim it at the Lighthouse by speaking to Jossik at no cost to the player (when retrieved, lost prayer books contain all the pages that were previously added to them). Also, with the unholy book and a rune crossbow equipped, a player's ranged attack bonus will just surpass the ranged attack bonus of the dark bow, although it is considerably lower than a sighted magic longbow (+140).

Prior to the release of the defenders, the unholy books were often used in conjunction with an abyssal whip or other high-level single-handed weapon because it provided the best offensive bonuses of any shield. However, all defenders mithril and above have higher melee attack bonuses, limiting the unholy book's use to mainly players using Magic, Ranged, and 1 defence pures. Unholy books used to cost around 1.7m before the Treasure Trails update. Since then, the price of the book has rapidly been rising.

Filling the Unholy book with all pages currently costs 0 coins. Note- Once you have filled the book you cannot take the pages out

Preaching
The player may preform certain ceremonies by right-clicking the book and selecting "Preach." 25% of the special attack bar is required to preach. The following are options that appear when preaching and what the player says upon selecting them.

Wedding Ceremony

 * Two great warriors, joined by hand, to spread destruction across the land. In Zamorak's name, now two are one.

Last Rites

 * The weak deserve to die, so the strong may flourish. This is the creed of Zamorak.

Blessing

 * May your bloodthirst never be sated, and may all your battles be glorious. Zamorak bring you strength.

Preach

 * Battles are not lost and won; They simply remove the weak from the equation. Zamorak give me strength!
 * Those who fight, then run away, shame Zamorak with their cowardice. Zamorak give me strength!
 * Battle is my calling, and death shall be my rest. Zamorak give me strength!
 * There is no opinion that cannot be proven true, by crushing those who choose to disagree with it. Zamorak give me strength!
 * Strike fast, strike hard, strike true: The strength of Zamorak will be with you. Zamorak give me strength!

Trivia

 * Since the God books of Guthix, Armadyl and Bandos are all called after the allignment of it's representing god, it is more (logically) consistent to call Zamorak's book "Book of Chaos", since he is the god of Chaos. This is the same for Saradomin's book. As he is the god of Order his book should be now called: Book of Order. But since Zaros isn't officially well known, his alignment isn't known, and all his other items are referred to as 'Ancient', it indeed makes (more) sense that his book is called: Ancient book.
 * The pages for the book were as low as 100k per page many years back.