123s of D&D Dungeons & Dragons - Rules of Play says:
Start your little gamer on an adventure to last a lifetime with this numerical children's book and introduction to the greatest roleplaying game of all time, Dungeons & Dragons. Written in the rhyming style of classic children's books and filled with adorable owlbears and darling beholders, adorable bugbears and darling drow, it's the perfect book to share the joy of Dungeons & Dragons with a new generation as they learn their numbers--a precursor to every new path in counting.