Ambush

	Ambush
When attacking an illuminated target from out of the darkness you ignore half the target's evasion and your critical chance is increased by 20% plus 0,3% for each stealth skill point.
Requirements Perception 6 Stealth 40

This situational feat can increase your critical hit chance even over 100%. At the minimum requirement of 40 stealth, it already gives a 32% (20+0.3*40) increase.

Ambush only increases your weapon critical chance, not the critical chance of psi skills.[1]