
Whether or not intended by Bethesda, plasma weapons won't penetrate any layer without the use of critical hits. with this perk will pierce anything, including multiple layers of walls and even the ground - useful for burrowing radscorpions and mole rats. At least some portion of the enemy must be visible to be able to target them in V.A.T.S., if they are completely behind cover and hidden, one will be unable to target them. With this perk it actually allows one to target their weak spots, through their body, meaning that even if they are facing towards the player character, it is still possible to hit exactly where wanted, such as fusion core. This is very useful against enemies like robots and people in power armor, because they generally have their fusion cores or combat inhibitors on their backs. This perk allows one to target their opponent's body parts even if they are behind cover, allowing them to shoot through solid objects and hitting the body part that they were aiming for. when you target an enemy's body parts that are blocked by cover, there is no decrease in accuracy. you can target an enemy's body parts that are blocked by cover, with a decrease in accuracy. ” - Fallout 4 Vault Dweller's Survival Guide description

This is another good option to further enhance V.A.T.S. “ There's no place to hide! This doesn't allow shooting through impenetrable walls but does allow you to target partially obscured foes (like those behind trees, through windows, or behind barricades) if parts of them are visible.
