Plotto (Tin House, $20, 350 pp.) is the most unique of literary tools. Created in 1928 by writer Canadian William Wallace Cook, the book serves as a "thesaurus of plots" – a master guide to the more than 2,000 types of conflict that Cook estimated form the basis of most plots. Original editions of the book are collector's items that can cost up to $400, but fortunately Tin House has released a sturdy new hardback edition that will set you back much less, and just in time for the holidays. "Plotto" is perfect for both aspiring writers and parlor games. (Good luck trying to think of a plot combination that's not in there.)