A group lead by N. Dukhov redesigned IS-2 with a lower silhouette and pointed hull.
The front armor on the IS-3 was made from two plates that were welded together at an angle. This was called a Pike nose by the IS-3's designers. It was hoped that this design would help it shed enemy rounds better than the IS-2.
N. L. Dukhov developed the rounded shaped turret which deflected rounds fired at it better. The internal layout was better for the crew and improved fighting efficiency.