From D&D Wiki
|This material is published under the OGL 1.0a.|
Shocking Burst: A shocking burst weapon functions as a shock weapon that also explodes with electricity upon striking a successful critical hit. The electricity does not harm the wielder. In addition to the extra electricity damage from the shock ability, a shocking burst weapon deals an extra 1d10 points of electricity damage on a successful critical hit. If the weapon’s critical multiplier is x3, add an extra 2d10 points of electricity damage instead, and if the multiplier is x4, add an extra 3d10 points. Bows, crossbows, and slings so crafted bestow the electricity energy upon their ammunition.
Even if the shock ability is not active, the weapon still deals its extra electricity damage on a successful critical hit.