Vital Sense

The Vital Sense mod increases critical damage by 20% per rank for a maximum of 120% at rank 5.

Stats
Critical damage = (final damage) * (base critical multiplier) * (1 + mod value)
 * Final damage: this is the damage a normal, armor piercing, or elemental attack would do after mods and armor or resistances are accounted for.
 * Base critical multiplier: like the critical chance, the critical multiplier also varies with the weapon being used.
 * Mod value: determined by the rank of the equipped mod, if any.