Shock Rune on a critical hit

[The Rot Grub]

The Shock rune has the following effect:

Quote:

Electric arcs crisscross this weapon, dealing an extra 1d6 electricity damage on a hit. On a critical hit, electricity arcs out to deal an equal amount of electricity damage to up to two other creatures of your choice within 10 feet of the target.

If you land a critical hit, the shock damage doubles to 2d6. If the electricity does "an equal amount of electricity damage to up to two other creatures," I assume the 2d6 you roll is the damage applied to the other creatures, yes? (Not just the base 1d6 electricity damage)

[Cordell Kintner]

No, you never double any damage that only occurs on a crit. The two creatures would take 1d6 damage.

[Wheldrake]

Although it's true that you never double extra damage that occurs on a critical hit, you do double base elemental damage from property runes, and the wording of the skock rune, doing "an equal amount of damage..." can be read to mean "equal to the electricity damage dealt by that critical hit."