The one thing that pretty much everybody agrees on is that at least there should be a downspout to deliver the water to the lower roof and point it in the right direction.
Gutter from one roof to another.
In this first picture one can see where the gutter has been cut off at the same pitch as the roof to let the gutter empty onto the roof surface.
Another word for gutter.
The water is allowed to run on the roof surface and is collected by the lower gutters.
A steep roof covering a house has a larger area and collects more rain than a shallow roof on a house of the same size.
A hole at the bottom of the gutter or an open gutter end will just splash water around in a heavy rain.
How effectively a steep slope asphalt shingle roof sheds rainwater is primarily a matter of roof slope and effective use of flashing including downspouts and gutters.