At tier 7 the Russian IS heavy tank doesn’t have an overwhelming amount of armor to stand up against tier 7 heavy tanks/tank destroyers and higher tier tanks.  However, its armor is strong enough in a lot of areas to give tier 5/6 and many tier 7 tanks a tough time in damaging the IS due to its armor layout.  The thickest armor is only 120mm however the IS does a very good job at limiting the amount of thin armor in the “usual” weak spots on tanks and the vast majority of the IS is 90mm-120mm.  This gives the IS heavy tank good all around armor that can take a beating from some tanks but won’t hold up against opponents with good penetration.

This guide is for World of Tanks IS weak spots and will break down the IS heavy tank into different areas based on effective armor values.  The weakest armor is highlighted in green, followed by yellow armor, and red areas are the strongest sections of armor on the IS heavy tank.  Purple areas are sections with no hull armor behind them and/or areas with a high chance of a zero damage critical hit.

IS Frontal Weak Spots

Frontally the IS has most of its strongest armor around the edges of the tank since the turret cheeks and the sides of the upper hull armor are angled horizontally.  The main areas to focus on for the front of the IS are the sections of hull armor that are not angled very well, the center of the commander’s cupola, and around the gun/left of the gun.  The frontal lower glacis varies from 120mm at 3 degrees to 100mm at 30 degrees but at most is only 120mm effective armor.  Part of the upper glacis is 100mm at 47 degrees giving it 147mm effective armor which is still somewhat weak.  To finish off the hull weak spots you have the driver section below the turret that has a maximum 150mm effective armor values and a zero armor hole where the view port is.

On the turret around the gun you have a 100mm mantlet with no armor behind it in the green sections and then to the left of the gun two viable areas on the frontal turret armor.  The commander’s cupola is located on top of the IS heavy tank and is weak as long as you avoid shooting towards the edges where the armor is significantly stronger.

IS Side Weak Spots

The side of the IS heavy tank is much weaker than the frontal armor and is easy to damage as long as you avoid the thick frontal armor that bends around from the front of the tank.  For tanks that could struggle against armor up to 160mm effective armor avoid the yellow areas on the turret since some areas are on the higher end of 106mm-160mm.  Otherwise the side has plenty of larger areas to hit that should not pose a problem to any tank that usually faces the IS.

IS Rear Weak Spots

The rear of the IS is very weak aside from some small areas on the back of the turret and also the commander’s cupola.  Simply avoid hitting these few small areas and you will have no trouble with damaging the rear of the IS heavy tank.