Orson Scott Card, as proved by his success, is one of the great science fiction writers of our day. Anyone who has read Ender's Game should agree. That stories huge plot twist blew my mind. Anyways, I have read some of his books on writing and he brought up an interesting point that I would like to discuss- the rules of giving powers. Basically he advised that powers should come with a cost or requirement. A good, simple example is the recent game Infamous and its sequel. The protagonist has electric powers but runs down just like a battery. In one of my novels, a druid must use his own blood to control plant-life. Card's reason is that it keeps the suspense high, knowing that there is a cost to the power being used. Not all writers follow this rule, especially some superheroes. I think that it is a very effective way to use powers. Otherwise, the character is less believable and it's harder to think they will fail. What do you think? Do you think it's important to do or do you think there are exceptions?