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.