Alvin Plantinga's free will defense is based on the idea of transworld depravity. Plantinga claims that if every essence suffers from transworld depravity, then it is not possible for God to actualize a world in which there is moral good but no moral evil. I describe possible worlds that imply it is impossible for every essence to suffer from transworld depravity. I then show how to modify the concept of transworld depravity to avoid this problem, and formulate an alternative free (...) will defense that is based on the concept of unobtainable worlds instead of transworld depravity. (shrink)