The Collection Book allows Fortnite: Save the World players to slot people and schematics for Collection Book XP. When you slot certain schematics you may never be able to unslot it again unless you get a new copy of the same item! If you do decide to unslot a schematic in your Collection Book, it will cost you 30 v-bucks. Some schematics can be researchable too allowing you to obtain a schematic you haven't already slotted. As you increase your XP, you gain Collection Book levels. Each level will give you small rewards such as schematics, various types of XP, and loot llamas. When items are available to slot in a tab, a yellow number will appear on the tab (as seen in the image above) depending on the number of available items in that specific tab.
Collection Book Layout
The Collection Book can be confusing when you first open it. On the left is a large list of categories. When you click on one, it opens a dropdown menu with each subcategory within the category. For weapons, there is also a Crystal subcategory. Don't worry about this until much later, these are just Evolution Rating 4 weapons. When you click on a subcategory, it displays all of the sections within the subcategory on the right. Each section has specific items of one type. Confused yet?
Slotting People & Schematics
Depending on the rarity of the item (Rare, Epic, etc.) you will gain various amounts of Collection Book XP. When an item is slotted in the book, it will no longer be grayed out. You can select the item and view its details, including perks, stats, and more.
Levelling Up Slotting Items
When you slot something, you can actually continue to level up the item, and even evolve it! This will reward you with extra Collection Book XP, but not by very much. You should wait until the book is nearly filled before beginning to max everything out!
In the top right of the screen, the Page Completion is displayed. For example, 13/32 shotguns in the image above. Certain categories have rewards for Page Completion, as well as for Section Completion. Currently, only the Fortnitemares Costume Party 'Attendees' have this added rewards feature.
As you gain Collection Book, you gain XP for it, earning rewards every level. You can view upcoming rewards for the next 3 levels, as well as the next major milestone in the book. Some rewards have you choose between given options, such as one of the four hero classes.