You may have heard of this common fantasy trope, an archer firing multiple (usually 3) arrows in a single pull of the bow. 

Now, I am not an expert at bows or tactics, but it seems to me that the loss of accuracy is not worth even attempting this and that's assuming it could work! 

What problems appear with this 'Multi-arrow' bow and how can I overcome these? What are the actual realistic advantages and disadvantages of a multi-arrow bow if it could work?