How is it determined if your target is crippled or not when you get a critical hit? Is it the same chance on any critical, or is it based on how much damage the critical does? Also, will a critical hit do more damage if it hits for instance the torso instead of an arm?
EDIT: On a side note, why is there an option to make an aimed shot on the torso when according to the wiki you don't get any bonus critical, can't cripple the target and pay 1 extra AP for it? What am I missing?