If you have different levels to your roof, you might have gutters on both levels. While this isn’t a problem in itself, the way that the gutters drain could prove to be an issue. Some will have the gutters draining onto the roof below with no downspout at all, while others have a downspout that ends at the next level of the roof. Both of these methods of drainage can potentially do harm to your home. It could lead to water damage, moss growth, or algae growth on your roof. It might not seem like much, but all the water collected from a section of the roof draining on a different section can be quite harmful.
The correct way to run the downspout is to have it drain into the gutter at the bottom of the roof. While this will require more work, and it might look unsightly if there is no place where you can hide away the downspout, it will be the best thing for your roof.