4e Mechanics & Rules Discussion

[Raellus]

I want to check my understanding of the Critical Injury rules (which are as follows).

CRITICAL INJURY: If the damage inflicted, after mitigation
by armor and cover, is equal to or higher than the crit
threshold of your weapon, you also inflict a critical injury
on the target.

Some weapons' Dam and Crit numbers are the same, so conceivably a single hit could generate a Critical Injury. However, most weapons' Crit number is higher than its Dam number (usually by one).

My question: For weapons in the latter category, is using ammo die the only way to generate a Critical Injury?

OR

Could Critical Injuries be generated from a scenario like the one that follows: In round 1, the player hits a target in the right arm for 2 damage (the player's weapon's Crit value is 3). In the next round, the player hits the target in the same arm for another 2 damage. Since the total damage to that body part is now 4, over the weapon's Crit score, is a Critical Injury generated?

Similarly, what if the player hits a different body part in the second round, still causes 2 points of damage. Now that the total damage to the target is 4, over the weapon's Crit score, is a Critical Injury generated?

In other words, does only the damage from a single shot or burst count towards generating a Critical Injury? Or, does cumulative damage do so as well? (And, if so, is it cumulative to a single body part, or cumulative for the target's entire body?)

Thanks, in advance.

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