The answer to the Series of 12 WWI battles on Italian soil 1915-17 in CodyCross is ISONZO. CodyCross is an amusing word game. It is a word play game that challenges one's word knowledge in different categories and themes. If this clue had you baffled, you're not alone! Many of the puzzles in CodyCross are pretty tricky, but that's what makes the game so fun.