A unit with Double Damage is indicated by a "x2" next to its damage value.
What Does Double Damage Do?
When a unit with Double Damage attacks, it does twice the normal damage indicated on the card.
What's the point of that? Why not just give the unit twice as much damage to start with? Well one reason is buffs: if you use a "+1 damage" buff on a Double Damage unit such as Renegade Valkyrie then it effectively becomes a +2 buff. Double Damage works especially well in decks with lots of Warcry units.
At the moment (card set 1) there are no weapons or other attachments that give Double Damage, but that might change in the future.
Note that Double Damage is a fixed skill, it's not 'Damage Times x' so it doesn't stack.
Last updated: 18-02-2017
This page written for Eternal version 1.15, Card Set 1