movement in darkness

[RObiN-HoOD]

If a drow casts a darkness spell, and you are not near the drow to attack even with a 50% chance, how do you now where to move in the darkness to go near the enemy if the enemy himself moves in the darkness? Can you understand him from listen? perhaps something else?
(official rules please if possible)

 

[EOL]

Use the invisibility rules on page 78 of the DMG. It's basically the same thing.