Stagger

Stagger or Staggered is an action and condition in Fallout 3, Fallout: New Vegas, Fallout 4, and Fallout 76.

Fallout 3 and Fallout: New Vegas
To stagger others refers to dealing damage that causes one to walk or move unsteadily, as if about to fall. The player is immune to the stagger affect, but can cause it enemies. The only consistent method to cause stagger is to cripple a limb. Crippling a limb puts an enemy in pain state where they stop all actions and grasp or recover from the limb that was just crippled; leaving them open for subsequent attacks.

Fallout 4
Both the player character and some enemies have the ability to stagger. For the player character, crippling limbs still causes a stagger state, and some perks also give weapons an inherent stagger chance. Attacks from enemies, such as the Deathclaw and Yao Guai, have a chance to stagger on heavy attacks. The yao guai in particular has a 100% chance to stagger.
 * Stagger perks
 * Commando
 * Heavy Gunner
 * Pain Train
 * Stagger reduction
 * Pneumatic torso mod

Fallout 76
A stagger in-game will be a brief moment where the target is locked in place and and performs a stumbling animation, cancelling actions and leaving the actor open to further attacks. All weapons stagger in different magnitudes - small, medium and large. This affects the degree of camera shake as well as duration. Stagger occurs when a limb is crippled or upon perk activation. Some enemy attacks will have a chance to stagger on-hit.
 * Stagger perks
 * Bow Before Me
 * Enforcer
 * Heavy Gunner
 * One Gun Army
 * Pain Train
 * Tank Killer
 * Stagger reduction
 * Pneumatic torso mod