From the publisher's website:A Word Trek Puzzle is a pair of words with the same number of letters (For Example: dog / cat). The objective is to transform one word into another word, through step-by-step transformations. Using paper and pencil, players either change or rearrange (anagramming) one letter from the first word to make another valid word. (For Example: dog, dot, cot, cat.) WORD TREK develops logical thinking while building vocabulary and improving spelling skills. - BoardGameGeek