The Ironclad starts with 80 HP, Bash and Burning Blood, which heals 6 HP at the end of every combat in both games. Most Ironclad decks are built around one of three card groups: Strength, Exhaust or Block. Numbers below are for Slay the Spire 1 unless marked, with the upgraded value in brackets.

Strength

CardCostEffect
Inflame1Gain 2 (3) Strength
Demon Form3Gain 2 (3) Strength at the start of each turn
Limit Break1Double your Strength, then Exhaust (upgrade removes Exhaust)
Heavy Blade214 damage, Strength counts 3 (5) times
Rupture1Gain 1 (2) Strength whenever you lose HP from a card

Rupture pairs with cards that cost HP, such as Hemokinesis (lose 2 HP, deal 15) and Brutality (lose 1 HP and draw 1 card each turn). For how Strength interacts with Weak, Vulnerable and multi-hit cards, see how attack damage is calculated.

Exhaust

CardCostEffect
Feel No Pain1Gain 3 (4) Block whenever a card is Exhausted
Dark Embrace2 (1)Draw 1 card whenever a card is Exhausted
Corruption3 (2)Skills cost 0 and Exhaust when played
Second Wind1Exhaust all non-Attacks in hand, gain 5 (7) Block for each
Fiend Fire2Exhaust your hand, deal 7 (10) damage for each card
Burning Pact1Exhaust 1 card, draw 2 (3)
Exhume1 (0)Return a card from your exhaust pile to your hand

With Corruption and Feel No Pain in play, every Skill costs 0 and gives 3 Block when it Exhausts, on top of its own effect.

Block

CardCostEffect
Barricade3 (2)Block is not removed at the start of your turn
Entrench2 (1)Double your Block
Body Slam1 (0)Deal damage equal to your Block
Metallicize1Gain 3 (4) Block at the end of each turn
Juggernaut2Deal 5 (7) damage to a random enemy whenever you gain Block

Barricade keeps Block between turns, so Entrench and Body Slam grow with every turn of the fight.

What Slay the Spire 2 changes

Not in the StS2 Ironclad pool: Limit Break, Heavy Blade, Brutality, Metallicize, Entrench, Exhume and Spot Weakness.

CardStS1StS2
Juggernaut5 damage per Block gain6 damage per Block gain
RuptureStrength when you lose HP from a cardStrength when you lose HP on your turn
CorruptionRareAncient

New StS2 Ironclad cards for these builds:

  • Cruelty: Vulnerable enemies take 25% more damage.
  • Unmovable: the first time you gain Block from a card each turn, double it.
  • Colossus: gain 5 Block and take 50% less damage from Vulnerable enemies this turn.
  • Hellraiser: whenever you draw a card with "Strike" in its name, it is played against a random enemy.
  • Thrash: deal 4 damage twice, then Exhaust a random Attack in your hand and add its damage to Thrash.

Two Ironclad cards appear only in multiplayer runs: Demonic Shield (give another player Block equal to yours) and Tank (you take double damage from enemies, allies take half).