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[Sorry to interject but, rock is a completly different element from ground. Like in pokemon you can have a ground rock type but you can also have a ground water type; iif you were to hit a rock type with a water attack it would be practicly a one hit k.o., but if you hit a ground type with a water attack it would do almost nothing, a ground rock type is vunerable to water attacks but they would do a little bit more than normal damage; while a water ground type when attacked with a water attack would do nothing at all. Sorry koga but i have to agree with Owen on this.]