Word chains or ladders have been a source of challenge and enjoyment since their invention as "doublets" by Lewis Carroll over a century ago, in 1879. They were called Transformations by "Professor" Hofmann. Despite significant advances since Ross Eckler published his first study of word graphs (networks), there still remain challenges for those who relish hard work, and easier challenges for those seeking mere enjoyment.
"Snakes and Ladders,"
Word Ways: Vol. 31
, Article 3.
Available at: http://digitalcommons.butler.edu/wordways/vol31/iss2/3