Lorebook
At 1st level, you have a lorebook containing six 1st-level wizard spells of your choice and your collected notes on magical theory and the world.
The spells that you add to your lorebook as you gain levels reflect the arcane research you conduct on your own, as well as intellectual breakthroughs you have had about the nature of the world and the peoples in it. You might find other spells during your adventures. You could discover a spell recorded on a scroll in an evil wizard's chest, for example, or in a dusty tome in an ancient library.
Using the Book's Information. Your lorebook contains your thoughts and observations, as well as those notes you've taken from others in compilation, on the world around you and the people in it. So long as you have your lorebook and 1 minute to reference it, you gain advantage on your next Knowledge skill check relating to a location, person, creature, or event that is contained in your lorebook.
Copying a Spell into the Book. When you find a wizard spell of 1st level or higher, you can add it to your lorebook if it is of a level for which you have spell slots and if you can spare the time to decipher and copy it.
Copying a spell into your lorebook involves reproducing the basic form of the spell, then deciphering the unique system of notation used by the wizard who wrote it. You must practice the spell until you understand the sounds or gestures required, then transcribe it into your lorebook using your own notation.
For each level of the spell, the process takes 12 total hours and costs 5 gp. The cost represents material components you expend as you experiment with the spell to master it, as well as the inks and paper you need to record it. Once you have spent this time and money, you can prepare the spell just like your other spells.
Replacing the Book. You can copy a spell from your own lorebook into another book-for example, if you want to make a backup copy of your lorebook. This is just like copying a new spell into your lorebook, but faster and easier, since you understand your own notation and already know how to cast the spell. You need spend only 4 total hours and 1 gp for each level of the copied spell.
If you lose your lorebook, you can use the same procedure to transcribe the spells that you have prepared into a new lorebook. Filling out the remainder of your lorebook requires you to find new spells to do so, as normal. For this reason, many wizards keep backup lorebooks in a safe place.
The Book's Appearance. Your lorebook is a unique compilation of spells, with its own decorative flourishes and margin notes. It might be a plain, functional leather volume, a collection of scrolls, or even a loose collection of notes scrounged together after you lost your previous lorebook in a mishap.