|Basic (1 pt): Increases your melee weapon concealment by 2.|
|Ace (3 pt): Enemies make 95% less noise when shot or meleed to death.|
The basic version basically increases the player's concealment by 2.
When civilians or guards are heavily injured or killed, they will always scream. This scream is audible to other guards or civilians within a 6 meter radius, even through walls or floors. As a result, it is very risky to kill guards or civilians in close proximity to other humans. Acing this skill will reduce the sound radius of the scream to a mere 0.25 meters. Chances are, if an enemy is within this sound radius, they are also likely close enough to see the body, so the remaining noise has no negative impact on gameplay.
For the basic version, obtaining the skill basically guarantees a +2 concealment as all melee weapons have concealment values which affect the detection risk. Thus the skill is extremely advantageous in stealthing heists while using less concealable weapons, as well as making it easier to obtain the bonuses from Sneaky Bastard and Low Blow.
The aced version of the skill is identical to the effect of Shinobi's aced version, offering a 95% decrease in sound for NPCs killed, and could be equally important for stealth -- either skill makes it much easier to kill guards even when in close proximity to other NPCs. The effects do not stack to give a 99.75% reduction in enemies' noise, nor would there be any practical impact on gameplay if they did. Therefore, acing both skills is redundant. Hidden Blade should not be aced if Shinobi has already been aced, and vice-versa.
- The name and effect of this skill are references to the highly concealable assassination weapon of the same name in the Assassin's Creed series.
- The icon of the Skill depicts the Compact Hatchet from the Gage Assault Pack, and the Trench Knife from the Gage Historical Pack, the latter released after the Fugitive tree.