Books

Books or Tomes
There are 5 different books or tomes in the game, but what do they do exactly?

Note: All require a key to be used.

Tome of shields
This tome applies a shield to all living heroes equal to the HP of all heroes. Basically turning every hero into multiple. This is a one time use and only lasts until the shield(s) are depleted or when you time loop.

Usefulness: Meager.

Gratogmorr
Using this tome will double your current amount of gold once. Nothing more. It will only double gold up to an amount of 100.008e+300.

Usefulness: Negligible

Wizard's Note
This nifty little tome increases the odds of success for all listed quests + next quest to their maximum. Upon use an active quest will be completed and its chance of success changed to the tier's maximum. (25% for the first, 60% for the second and 95% for the bottom one; with a Shaman’s Tamboorine of the fifth level - 30% / 65% / 100%).

Upon collecting the finished quest, another will instantly appear with maximum chance. No more waiting. As long as a quest touched by Wizard's Note is in the quest list, it will not be replaced by another. You need to complete the quests first, before a new one will appear.

Usefulness: Nifty.

Book of passage
Using this book allows you to travel to the crossroads. This will allow you to either go back to the start of the zone (When not at the end of the zone) or skip a zone (10 levels). While it could be considered useful, the fact that it requires a key makes it not as efficient as you might think. You're better off getting the COMPASS artifact as that will allow you free passage to the crossroads.

Usefulness: Not really.

Summon friend
This very useful book will allow you to summon a maximum of two friends at your side... or uhm... screen. As soon as you use this book, a circular icon will appear in the bottom left of your screen. When you click it, the 'Helpers' screen will open.

At the top you will see the timer. This is how much time you have left until it expires. Yes, this book stays for a limited amount of time. 24 hours to be exact. After it expires it will simply disappear without any notification

Besides showing up in your options, your own secret code also shows up around the middle of this little screen.

Those two mouse grey areas are the locations for your friend's code(s). Click at the location of the "W" and you are able to enter a friend's code. (Note: If this is your first time using this book, both areas will be completely empty. I left them there, because some people seem to have trouble activating the text field)

Once you have entered 1 or 2 codes, press the save button. When you click the helper icon again, you can see some new information. It is important to note that in order to get "Assists shots", your friend needs to either actively click or have his fay fight for him. This relies on cast MAGIC BOLTS and nothing happens if not a single bolt is cast.
 * 1) If it's a functional code, then a name will appear next to "Assists shots". Otherwise it will remain blank.
 * 2) Is it the right name? If not, then either you received a code of someone else or miss-typed the code.
 * 3) If the number behind "Assists shots" is increasing, then it means your friend is busting his ass off, trying to get you through the levels.

Note: Some users have problems getting this to work.

Looks like they are not worth buying
They are most definitely worth buying. "But but... you said they are useless!". Regardless of their "usefulness", they are most definitely worth buying. This probably sounds a bit like insanity, right?

I would have to agree with you on that one. However, their usefulness lies in their being there on your shelves. You can have a maximum of 10 of each book and THAT... is where their usefulness shows.

Once you have maxed all 5 books, they will no longer show up in your quest list. This means that the more valuable quests show up more often. More ring quests. More artifact quests. More gem quests. More runestone quests and more key quests. (Although the key quests aren't really that great). Still... no more book quests.

There is also one particular exception to their uselessness. Eventually, later on in your gaming "career" you will likely find that you are eventually overflowing with Manacoins, in the thousands. They might as well be used somehow. The only two uses of Manacoins are Bamul's shop for the books and Mimic Chests, with the latter also requiring green gems to use. There is one, and only one, practical use for Manacoins that doesn't require green gems, and that is the Wizard's Note. With your book stockpile full, the remaining quests that can show up are for much more useful items: permanent boosting artifacts, hero rings, purple Runestones, keys and even green Gems. If you have the keys for them, doing an extended burst of Wizard Note quest runs (use the book to finish a good quest, buy a replacement immediately to fill your stock then repeat) could get you a good burst of artifacts and resources more useful than what ordinary chests could with those keys.