Cost: 2.

Requirement (). (While paying for this card, spend the listed resources.)

Hero Action (attack): Exhaust your hero → deal damage to an enemy equal to the total of your hero's THW, ATK, and DEF values.

Ironheart #17.
Go All Out

Go All Out has the potential to be the highest damage attack in the game, and its in leadership of all aspects!

The energy resource requirement is fine on a 2-cost card, but exhausting your hero as a cost means we need to compare the overall damage of this card versus the opportunity cost of missing a basic attack power. Generally the lower a hero's ATK and the higher their THW and DEF, the better this card will be for them.

Damage can obviously be increased using stat boosts. (Remember that ATK boosts would also increase a basic attack.)

3 Damage Base: Ms. Marvel, Quicksilver

4 Damage Base: Adam Warlock, Drax, Hawkeye, Iron Man, Nova, Rocket Raccoon, Spider-Ham, Valkyrie, Wasp (tiny)

5 Damage Base: Captain Marvel, Colossus, Doctor Strange, Spectrum (energy form included), Star-Lord, Thor, War Machine

6 Damage Base: Ant-Man (tiny), Black Panther, Black Widow, Captain America, Gamora, Ghost-Spider, Groot, Hulk, Ironheart (version 1), Nebula, Shadowcat, She-Hulk, SP//dr Suit, Spider-Man (Miles Morales), Spider-Man (Peter Parker), Spider-Woman (including Superhuman Agility for playing the leadership card), Venom, Vision (Dense)

7 Damage Base: Ant-Man (giant), Ironheart (version 2), Wasp (giant)

8 Damage Base: Ironheart (version 3)

Conclusions: Averages 4 damage for 2 resources when taking into account missing a basic attack. This is not terribly impressive on the surface but it does scale exceedingly well with supporting cards.
Spider-Woman has the highest non-infinite damage potential, currently her magical Christmas land damage number can reach 58 damage, or 64 with Doctor Strange helping. The actual number would be a lot less but it is still possible to one-shot a villain stage without gimping the entire deck.
Ant-Man, Spectrum, and Wasp are all even better than they seem because they can very easily trigger Moxie.
Quicksilver was already using leadership for OTK combo plays and this leans even further into that.
Yet another reason Doctor Strange loves the leadership aspect, as it gives him high burst damage with his Magical Enhancements that he previously was not really using.
Finally, steer clear when using Venom because the opportunity cost needs to include not using his two Venom's Pistol on his basic attack. It is also exceptionally poor for Ms. Marvel who needs to give up her Morphogenetics.

The_Wall · 127
It seems odd to think that Go All Out might be the highest attack card in the game when Mass Attack exists. The sum of your THW and DEF are not usually going to be higher than the sum of three allies, and some of the big boosts (such as Blaze of Glory and Avengers Assemble) provide twice as much damage to Mass Attack. In addition, Mass Attack doesn't exhaust your Hero, so you can get the benefit of any ATK boosts twice that turn. Mass Attack typically starts at 8+ damage and can go through the roof - especially in a Spider-Woman or Gamora deck that can pick three allies with Enraged and Energy Spear (and more) attached. — Death by Chocolate · 4
Nope. The opportunity cost of Mass Attack is that you don't get to attack with those 3 allies that turn. Go All Out blows it out of the water when you figure that those allies would have dealt their damage ANYWAY. At that point you are comparing Mass Attack to anything that gives them another swing... so Vapors of Valtorr I guess. You are also talking about a completely different playstyle of going wide and cycling your deck at least once and probably twice. So I would have played 3 Go All Outs before you actually get your first decent Mass Attack. And technically I am correct given that Ant-Man can deal infinite damage (although as I mention he can also do this with a basic, but NOT with Mass Attack). — The_Wall · 127
Brain fug, disregard not being able to go infinite with Mass Attack (you can), but everything else stands ^_^ — The_Wall · 127
You seem to mistake my disagreement for a claim that Mass Attack is a better card, which I have not done. I am disputing your opening claim of your first sentence. That said, I do disagree that you could have just attacked with those allies anyways, when they're all enraged and it would take a lot to block that consequential damage every turn. For further reference, I have played the Mass Attack Gomora deck, and while you may be able to play 3 Go All Outs by the time I play my first Mass Attack on round 6, who cares? I can then proceed to play 27-36 damage Mass Attacks every single turn for the rest of the game. — Death by Chocolate · 4