Zamorak's Book of Chaos

Zamorak's 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. 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).

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 40 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. 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). Although a Chaotic crossbow with an Unholy Book will have almost as high ranged attack bonus as the sighted magic longbow, with +128 compared to the sighted longbow's +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. Despite this, it is the most popular, and by extension the most expensive, of all God Books. Unholy books used to cost around 1.3m 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 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.

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 alignment of its 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 (in order to maintain consistency), 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, for the most part of 2007-2008, approximately 250k. They went as low as 100k per page in late 2008/early 2009, before rising to their current prices.
 * Although this book is not considered a piece of ranged equipment, it has the highest ranged bonus of any item in the off-hand slot.