There is a great protective case for the iPad. It is called a Survivor Case. It will protect your iPad from spills, drops, even wind and rain. When this case is on, the iPad is pretty much indestructible for the little ones. They also have some pretty cool kid cases on line. One looks like a little "Gumby" character. It also has a rubber case around it and looks pretty protective. I think your 18 month old would be fine if one of these cases were on it.