Arcing (3.5e Equipment)
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Arcing: An arcing weapon has the characteristics of a shock weapon, but the energy arcs to additional targets on a successful critical hit. The electricity does not harm the wielder. When an arcing weapon lands a successful critical hit, the electricity arcs to a number of additional targets depending on the weapon's critical multiplier. If the weapon has a x2 multiplier, the target of the attack and one more target of the wielder's choice are both dealt 2d8 electricity damage. If the weapon has a x3 multiplier, one more target can be chosen than if the multiplier was x2, for a total of three targets. If the weapon has a x4 multiplier, one more target can be chosen than if it were x3, for a total of four targets. This damage replaces the electricity damage usually dealt, and the damage for each target is the same; do not roll separately for each target. Each target must be within 20 ft. of the previous one, and nothing may be targeted more than once for the same critical. All targets beyond the first are entitled to a reflex save (DC 17) for half damage.