How to Beat The Heart in Slay the Spire

The ultimate challenge in Slay the Spire starts to make some sense.

by Bhernardo Viana
The art shows Ironclad slashing The Heart, climbing up the final stairs of The Spire while burning, and a flame on the top of the tower.
Image via Mega Crit Games

Oh, I’m sorry to hear you died to The Heart on turn three again. It literally happens to even the best Slay the Spire players. I’ve died to it multiple times even with decks that simply demolished the Act 3 bosses.

Beating The Heart – or should I say stop its beating? – requires a combination of good deck building, chasing relics, stocking the right potions, and your best decision making. The Heart’s attacks and skills are so brutal you need to prepare yourself to fight it as early in your run as possible, sometimes taking cards and saving potions that you otherwise would not.

To destroy The Heart, you must learn how it destroys you. As some Slay the Spire players say, you need to understand how to solve The Heart, which means dealing with whatever threats it throws at you.

All following information is applicable to any level of play, including Ascension 20.


If you feel confident about your Slay the Spire knowledge, feel free to click any of the links below to move to the section that will serve you best. Otherwise, scroll down for the full ride.

How The Heart beats you in Slay the Spire

The Heart is a juggernaut with 750 health points up to Ascension 8 and 800 from Ascension 9 onwards. It has the following powers to make your attempt painful:

Beat of DeathWhenever you play a card, take X damage.Take 1 damage up to Ascension 18
Take 2 damage on Ascension 19 or higher.
InvincibleCaps all damage and HP loss taken to X each turn.300 up to Ascension 18
200 on Ascension 19 or higher

The powers alone are enough to kill you, and it’s part of the initiation to Slay the Spire to die at least once to Beat of Death because you forgot to block. Not that I ever did this.

Also, it’s impossible to one-shot the heart due to Invincible. Up to Ascension 18, it forces you to spend at least three turns to kill it, and in higher ascensions, at least four.

The Heart can disintegrate you with the following attack pattern:

  • Turn one: Applies a debuff to make you take 50% more damage, reduce your attack damage by 25%, and reduce your block gained from cards by 25%, all for two turns (2 Vulnerable, 2 Weak, 2 Frail), in this order. Adds one of each status cards Dazed, Slimed,  Wound, Burn, and Void into your draw pile.
  • Turns two and three: Attacks for 40 (45) damage with Echo or 2×12(15) damage with Blood Shots, in either order.
  • Turn four: Buff
    • 1st Buff (turn four): Artifact 2
    • 2nd Buff (turn seven): Beat of Death 1
    • 3rd Buff (turn 10): Painful Stabs
    • 4th Buff (turn 13): Strength 10
    • 5th Buff onward (turn 16, 19, 22[…]): Strength 50

That means you really want to kill The Heart before on turn 17 at most. The 10 strength it gains on turn 13 is already a menace, so killing it before that turn is your best option. I already went beyond that, but my character didn’t live to tell the story.

Beating The Heart in Slay the Spire

The main questions The Heart asks you with all its attacks are:

  1. Do you have enough health or block generation to play cards while taking damage from Beat of Death?
  2. Can you protect against or get rid of debuffs?
  3. Can you handle Status cards?
  4. Can you handle a buffed opponent?
  5. Can you deal 750(800) damage in 17 turns at most?
  6. Can you block or resist at least 40(45) damage per turn?
  7. In a worst-case scenario, can you block or resist up to 240 damage (16×15) if you can’t kill The Heart by turn 14?
  8. Do you rely on debuffs to kill enemies? If so, can you burn through 2 stacks of Artifact reliably?

Solving most of these questions is your goal when building your deck, when looking for relics, and when saving potions (looking at you all who love to pick Sozu). 

You don’t need to solve all of them, though. If you can consistently get absurd block numbers like using Barricade and Entretch, you don’t care about Beat of Death damage or even being Frail. The same way, If you can deal massive damage in a few turns, like 100 or more Poison stacks with Silent by turn four, you never have to care about dealing with The Heart’s late-fight buffs or removing its Artifact.

The Heart always reminds me that I have other questions that I should have answered throughout my run –which will cost me the fight if I didn’t:

  • Can I get the right cards in my hand at the right time (do I have card draw and hand manipulation)
  • Do I have enough energy to play my cards (do I have energy generation and scaling)?

I will not talk about these broader deckbuilding and gameplay concepts since this guide is already long enough. First, I’ll talk about answering the eight main questions with potions, relics, and Colorless cards any character can use. Then, I’ll go over what each character has on their own belt to cut through The Heart.

All answers consider the worst-case scenario, where you’re on Ascension 19 or higher. If you’re not, these solutions will be even more effective for you since The Heart will be weaker.

Answers for The Heart with all Slay the Spire characters

Let’s break down the answers one by one.

  1. Do you have enough health or block generation to play cards while taking damage from Beat of Death?

In the Colorless cards set, these are my recommendations:

  • Finesse+ will give you four block, which makes the card pay for itself and give you block to play another one without losing health. The card draw is also very welcome, especially if you’re going for an infinite combo.
  • Good Instincts gives you six block for zero energy, enough to play at least two cards without losing health. Not as good as Finesse+ since you don’t draw, but I’m not sad if I have to use it.
  • Apparition’s Intangible reduces the Beat of Death damage to 1, which is also very helpful to take more value out of block cards.
  • Panic Button can work depending on your setup. It’s a lot of block, but ideally you want to have Artifact or debuff cleansing with Orange Pellets when using it against The Heart to avoid the block denial debuff.

Regarding relics, these can help you solve this problem:

  • Tungsten Rod is one of the most valuable relics against The Heart. It will reduce Beat of Death’s damage to one (or zero in low Ascensions), but only if you would take health damage. If you’re setting up block, you will still lose two points of it.
  • Anchor, Horn Cleat, and Captain’s Wheel all give you block when turns one, two, and three start, respectively. This gives you some buffer to safely use the cards you need to set up.
  • Centennial Puzzle is an indirect solution. Depending on your hand, it might be worth using a card when you have no block just to take damage and trigger this relic for the card draw to get what you need. I love doing so in the early turns.
  • Oddly Smooth Stone helps you get more value from direct block cards.
  • Ornamental Fan is a boost for Attack-heavy decks. Getting the four block will pay the cost of playing attacks that don’t generate it.
  • Calipers is great if you can scale and generate a lot of block every turn, like with Panic Button. It can snowball in later turns in block-heavy decks like Defect with Frost orbs, Iron Clad with exhaust cards and Feel no Pain, and Silent with Footwork.
  • Incense Burner gives you one stack of Intangible, which will reduce the Beat of Death damage.
  • It won’t look pretty, but Lizard Tail in a worst-case scenario can save you from dying to Beat of Death if you really need to play an important card and take that last hit.
  • The Abacus’ six block is nothing to scoff at when it triggers. That’s some free cards you can play after you shuffle your deck, which is especially useful when combined with Defect’s Reboot.

Be careful with these relics:

  • Torii just reduces attack damage, and Beat of Death is damage from The Heart’s power, so it won’t trigger this relic. It’s still a great relic against Blood Shots, though.
  • While Necronomicon is a great relic, it triggers Beats of Death a second time when it plays a copy of your attack. Make sure you can spare 4 block or health before activating it.
  • You will spend the Buffer from Fossilized Helix if you take Beat of Death damage, which happened to me on turn one more than I would like to admit. If you have this relic, always start the fight with block, or you will miss having it when The Heart attacks you for 45 damage.

Regarding potions, these are your best options:

  • Block Potion and Skill Potion can be useful if you’re having a setup-heavy turn where you need to save your energy for other cards.
  • Dexterity Potion helps, since it increases the value of your block cards.
  • Fairy in a Bottle is also a sad look for this case, just like Lizard Tail, but you might be forced to trigger it with Beat of Death in some situations.
  • Regen Potion is not ideal either, but it can recover your health if you were forced to spend it instead of blocking.
  1. Can you protect against or get rid of debuffs?

The list here is way shorter, so I won’t break it down by category. Here are your options:

  • Panacea will protect you from being Vulnerable and, if you upgrade it, from Weak too.
  • Clockwork Souvenir‘s 1 Artifact is perfect against The Heart. Just check if it’s worth spending it sooner, like denying debuffs from Wraith Form or Biased Cognition.
  • Orange Pellets is good in diverse decks that can draw consistently on turn two.
  • Ginger and Turnip make you immune to Weak and Frail, respectively. I love when I get them and essentially deny The Heart’s turn two.
  • The Odd Mushroom relic, from the Act 1 event Hypnotizing Colored Mushrooms, halves the strength of Vulnerable on you, making you take 25% more damage instead of 50%. It doesn’t solve the issue, but it helps.
  • Ancient Potion also gives you 1 Artifact (or 2 with Sacred Bark). Another great, energy-free and Beat of Death-safe protection against debuffs.
  1. Can you deal with Status cards?
  • The best way to handle Status cards is Medical Kit, which lets you play Status cards to exhaust them for no energy. If you see this relic late in your run, it’s probably worth buying it.
  • Card draw in general can help make up for the loss you have when you draw Status cards. Colorless cards like Impatience, Master of Strategy, Secret Weapon, Secret Technique, and Violence can get some useful cards in your hand despite the Status ones.
  • Draw potions Gambler’s Brew and Swift Potion also help you get useful cards in your hand when you draw Status cards.
  • Purity is your only Colorless option to exhaust Burn and Wound (and Slime for 0 energy).

Be careful!

  • While Runic Pyramid is an amazing boss relic, it retains Wound and Slime in your hand. If you have this relic, prioritize getting Purity or Medical Kid to not have your hand stuck with Wound, which can only be exhausted by effects. This is especially important if you go for the long Heart fight and The Heart uses Painful Stabs, which could fill your deck and hand with Wounds.
  1. Can you deal with a buffed opponent?

There’s no way to clear your enemy’s buffs in Slay the Spire, so the best you can do is either apply debuffs on The Heart or apply stronger and faster buffs on yourself to outscale it. Since you and I will talk about scaling your character in their own section, let’s chat about debuffing the Heart for now.

The key buff in this case is the Strength that The Heart gains every three turns after turn four.

  • Applying Weak to the Heart is very important. It gets you damage mitigation even if you’re Frail, and due to The Heart’s multi-attacks and high damage, you can protect yourself from damage more efficiently with Weak than with many block cards.
    • Blind is a zero-energy Colorless card that applies 2 Weak for no energy.
    • Weak Potion guarantees you 3 Weak on The Heart without depending on card draw
    • Event relic Red Mask only triggers on turn one, but it can be helpful if you also have a turn-one Weak effect you can stack to extend the duration of the debuff for the attacking rounds.
  • Reducing its Strength
    • Dark Shackles is The Heart’s worst nightmare. This Colorless Card can make even the strongest Blood Shoots deal zero damage thanks to its Strength debuff.
  1. Can you deal 750(800) damage in 17 turns at most?

I will talk about damage scaling since it’s the best way to reach this level of damage. You need some way to burst The Heart consistently either by buffing your character or debuffing the boss.

  • Applying Vulnerable is a good choice if you’re going for direct damage. The colorless card Trip, the Fear Potion, and the relic Bag of Marbles can all help you set it up. Hand Drill is useless since The Heart never gains block.
  • J.A.X from the Augmenter event in Act 2 is a Strength gain alternative. You might need other supporting cards to help you reuse it and gain substantial values of it, though.
  • Non-scaling Strength buffs like Strength Potion, Vajra, and Girya are always welcome, though alone they might not make the cut.
  • Flex Potion can help you set up a good burst turn. If you have Artifact and use this potion, you will spend the Artifact to avoid losing -5 Strength at the end of your turn, making you gain permanent +5 Strength for the rest of the fight.
  • Cultist Potion is great for this fight. We’re talking about a long run, so you will also gain strength and even outscale The Heart’s strength for a few turns if you use Cultist Potion early.
  • Uncommon relic Shuriken is a good Strength scaling option. Just be careful with Beat of Death damage, which will make each Shuriken activation cost you six block or health.
  • Pen Nib is an invaluable relic if you set it up properly before the fight. Doubling the damage of your attacks, especially after your scaling is set up, can make you end the fight faster. Just don’t be like me and forget to check its stacks while battling.
  • Necronomicon is great to take more value out of high-cost attacks like Dash, Heavy Blade, Doom and Gloom, and Wallop.

In the energy scaling front — since the more energy you have, the more damage you can deal — you also have a few options.

  • Madness will let you play expensive cards repeatedly, save some energy, or even set up infinite combos.
  • Non-boss energy relics that triggers fast and multiple times in one fight, especially those you can control their activation like Art of War, Mummified Hand, and Ice Cream are highly recommended.
  • Most boss relics that give you energy, such as Fusion Hammer and Coffee Dripper are welcome.
  • Some inconsistent energy relics can still help you depending on how you set them up before the Heart fight, such as Sundial, Happy Flower, and Nunchaku.
  • Ice Cream is a great relic to have overall, and you can use it to save some energy for a big turn you know you’re having soon. There’s no world where I’m sad picking this relic.
  1. Can you block or resist at least 40(45) damage per turn?

A huge part of blocking and resisting damage comes from item 4, where you’re reducing damage you’re taking in ways other than block. Here, we’ll talk about ways to consistently gain loads of block and scale it.

  • Panic Button is a great card if you have a way to prevent or clear its debuff or if you can survive a few turns without block.
  • Incense Burner and Apparition give you Intangible, reducing all damage taken to 1. You’ll survive pretty much any damage, but still must be careful with Blood Shots. Reusing or multiplying the card with character-specific cards like Exhume, Nightmare, Echo Form, and Omniscience makes it even better.
  • Resurrection methods like the potion Fairy in a Bottle and the relic Lizard Tail are good to have. If you know the next Echo attack will trigger them, play as many cards as you can without dying so you can take the most value out of your “spare” health. Just be careful because Blood Shots can burn through them, depending on how much damage you’re taking. I also already died that way.
  • Speed Potion can help you block more for one turn. Just like with the Strength from Flex Potion, you can keep this potion’s +5 Dexterity for the entire fight if you have at least one stack of Artifact before using it.
  • Non-scaling Dexterity buffs like Dexterity Potion and Oddly Smooth Stone can save you some health during this fight.
  • Just like with Shuriken, you can scale your Dexterity with a Kunai if you have block and health to spare to use attacks.
  • Fossilized Helix is a great relic if you can save its Buffer effect to tank Echo damage. Just make sure to not lose it to Beat of Death when playing cards.
  • Torii is an amazing relic against Blood Shots. As long as you’re taking 5 or less damage per hit, it will reduce that damage to 1. It’s like a mini Intangible against this attack.
  1. In a worst-case scenario, can you block or resist up to 240 damage (16×15) from Blood Shots if you can’t kill The Heart when it has 16 Strength on or before turn 14?

That’s a difficult question that is only really solved in two ways if we’re not talking about character-specific methods: Intangible from Apparition+ and Incense Burner or Dark Shackles to reduce The Heart’s strength. You ideally want to kill the heart before this point, because blocking that much damage will require absurd amounts of block scaling or precise card manipulation, such as retaining Dark Shackles for the exact turn you’re being hit by Blood Shots.

  1. Do you rely on debuffs to kill enemies? If so, do you have enough debuff generation to burn through 2 stacks of Artifact reliably?

In the previous items, I explained how debuffing The Heart helps with both dealing more damage to it and surviving its attacks. Therefore, in some scenarios you will want a good way to get rid of the two stacks of Artifact it gains on turn four. 

Here are some ways to do it:

  • Low-cost debuff cards. See item four.
  • Cards that apply multiple debuffs at once. Unfortunately, no Colorless cards do that, only character-specific ones.
  • Fear and Weak potions. It won’t look pretty, but if a debuff you need to apply via cards is more important than Weak or Vulnerable, it can be worth it.

Now let’s get to the characters part.

How to beat The Heart with Ironclad

  1. Do you have enough health or block generation to play cards while taking damage from Beat of Death?

Ironclad is an interesting character against The Heart, because you may sometimes want to take damage from Beat of Death to trigger card effects, like making Blood for Blood cost zero, or trigger relics effects like setting up block for the next turn with Self-Forming Clay.

Aside from these situations, here’s Ironclad tools to help you deal with that damage

  • Rage is a good card if you’re using lots of attacks, since its block will be added before Beat of Death triggers.
  • Shrug it Off, as in any point of the run, is a high value card since it also draws a new card. Many times its 8(11) block will be what you need to set up other cards.
  • Feel no Pain is an amazing option if you’re using lots of Exhaust.
  • During emergencies, Blood Potion can be good to recover any cheap damage you were forced to take from Beat of Death.
  • Runic Cube is a relic I wish I’m not forced to take in most of my runs. But if I do, I like to see it as turning Beat of Damage into my draw engine.
  1. Can you protect against or get rid of debuffs?

Ironclad has no real way of protecting against debuffs aside from the general relics mentioned in the first section. Just rely on them or outscale The Heart.

  1. Can you deal with Status cards?

Ironclad is probably the best at dealing with such cards. Here are some ways to do it:

  • Evolve is a great power that turns Status cards into a draw engine.
  • Fire Breathing is an average card against The Heart because its damage is too low. If you’re running additional Status-generating cards, its damage might be good.
  • Ironclad’s numerous cards that exhaust other cards are even better against Status, especially Burning Pact and Second Wind.
  • If your strategy is exhausting, running Dark Embrace and Feel no Pain is a great plus for extra draw and block.
  • Elixir is a potion that will also let you exhaust Status cards (and others) in your hand whenever you need.
  1. Can you deal with a buffed opponent?

Debuffing is another one of Ironclad’s strengths.

  • Disarm is a great skill to fully negate Blood Shots. Just be careful because The Heart always removes Strength debuffs when it buffs itself every three turns.
  • A bunch of Ironclad cards can apply Weak on The Heart, namely Intimidate, Clothesline, Uppercut, and Shockwave. Many times the former two will be your best choices since they also apply Vulnerable.
  • The Champion Belt will add Weak to all your sources of Vulnerable, making it a great relic overall and against The Heart.
  1. Can you deal 750(800) damage in 17 turns at most?

Ironclad is also very good at scaling damage. Here’s how to do it.

  • Strength scaling is the most obvious choice for damage on Ironclad. Limit Break is usually a key card to outscale The Heart, but first you need any source of Strength like Demon Form, Inflame, Spot Weakness, and others.
  • Rupture is a good card choice if you’re running lots of HP loss in your deck. Remember that this card does not work with Beat of Death damage.
  • The Red Skull common relic is perfect to get you that initial Strength you need for scaling when you’re under 50% HP. It’s scary, but I think it’s worth it if you have consistent block or healing.
  • Brimstone is a scary but very powerful relic to use. While it gives your enemies 1 Strength every turn, you get 2 Strength every turn. The outscaling is literally in the relic’s description. If you have effective ways to mitigate The Heart’s damage when using this relic, you can actually destroy it in six turns or less if you combine that boost with Limit Break.
  • The Paper Phrog will help you melt The Heart by making it take 75% more damage when Vulnerable.
  • The best finisher cards to take advantage of your extra Strength and the Vulnerable you apply are Heavy Blade and any multi-hit attacks like Fiend Fire, Pummel, Twin Strike, and even Sword Boomerang. Just be careful because some of these attacks can be underwhelming before you scale enough.
  • In heavily defensive decks with loads of block generation, Body Slam will be your star finisher.
  1. Can you block or resist at least 40(45) damage per turn?

Ironclad has a few ways of getting a bunch of block, which will help you survive the fight.

  • Impervious is an amazing 30 block unupgraded, nearly solving one entire early turn of damage in a single card.
  • Power Through and Second Wind can work really well if you’re running a deck that likes exhausts and can handle Status. Most of the times, you do want to exhaust some cards to thin out your deck, especially against The Heart.
  • Barricade is good, but it’s slow. If you don’t get it in your hand in one of the first few turns of the fight, it can feel like a Curse. Be careful and make sure you have lots of block generation along with Entrench.
  • Flame Barrier is a premium block card against Blood Shots. You block and deal up to 90 damage back (15 x 6, if upgraded), solving two problems at once.
  • Feel no Pain is an essential card for long fights with Ironclad decks. If you’re running a lot of Exhaust sources, you need Feel no Pain to make your fight a breeze.
  • You can stack a lot of extra HP with Feed throughout your run to help you survive some of these hits.
  • Blood Potion will be of good use if you had to take direct damage. Heart of Iron can also mitigate some of the damage thanks to the 6 Metallicize it applies, but these potions alone will not be enough. They’re just an extra.
  1. In a worst-case scenario, can you block or resist up to 240 damage (16×15) from Blood Shots if you can’t kill The Heart when it has 16 Strength on or before turn 14?

The best way for Ironclad to resist that much damage is setting up amazing block numbers with Barricade, any block cards, and Entrench in the previous turns. Aside from that, the best you can do is apply Weak and use Disarm on The Heart to mitigate part of the damage, but this alone will probably not be enough.

  1. Do you rely on debuffs to kill enemies? If so, do you have enough debuff generation to burn through 2 stacks of Artifact reliably?

Ironclad has Shockwave and Uppercut as his main cards to remove Artifact, though you might want to save the latter for the actual debuffs depending on the situation you’re in. If you can spare and exhaust it, it’s a good shot.

How to beat The Heart with Silent

  1. Do you have enough health or block generation to play cards while taking damage from Beat of Death?
  • After Image effectively reduces Beat of Death by 1 for Silent. If you’re in Ascension 18 or lower, your problem is solved. On Ascensions 19 and 20, combine that with Tungsten Rod and you’re done.
  • Other than that, you will have to rely on cards that generate block, especially ones that either give you card draw to “replace” themselves in your hand, like Backflip, or ones that won’t cost you energy, like Deflect.
  1. Can you protect against or get rid of debuffs?

Silent can’t protect herself from debuffs aside from the relics mentioned in the first section. Your best bet outside of them is to outscale The Heart.

  1. Can you deal with Status cards?

Silent’s way of dealing with Status cards is through discarding. This effect is best used if you get a secondary effect from discarding, like drawing more cards or dealing damage. 

  • Acrobatics is great, helping you get three cards to replace the one Status you will Discard. Prepared and Calculated Gamble, despite always resulting in a net loss of cards, will let you replace the Status as well and can be useful.
  • If you have any discard, getting Tingsha, Tough Bandages, and Hovering Kite to deal damage, gain block, and gain energy upon discard are a great plus.
  1. Can you deal with a buffed opponent?

I love how Silent can make colossal opponents hit like a pillow with her damage mitigation. Here’s how to make it easy to survive The Heart.

  • The ultimate way to survive is to use Wraith Form to tank the damage. If you can get extra copies of it with Nightmare, that’s the survival part of the fight almost completely solved. Heart failure guaranteed.
  • Malaise will help you get through one full cycle of damage thanks to the Strength down and Weak combo. Just remember the Strength debuff will be gone once The Heart buffs itself again.
  • Other Weak generation cards are good, but Leg Sweep is fantastic. You weaken your opponent and block at the same time, having the perfect damage mitigation and block generation combo in one card for a mere 2 energy.
  • Piercing Wail is probably the best common card Silent has for defense. One use of that and you’ve solved Blood Shots, fully negating its damage in either of the first two cycles if you’re not debuffed.
  • The Paper Krane relic will make your Weak more effective, which also makes The Heart fight a lot less scary.
  • Ghost in a Jar potion will be your emergency button to get a free Intangible turn to survive.
  1. Can you deal 750(800) damage in 17 turns at most?

Silent can be a little slow to ramp up damage, but she can do it easily with Poison scaling or with a little more difficulty with discard and direct damage like Shiv generation and Dash.

  • The prime Silent damage combo against The Heart is stacking some poison quickly on it with cards like Deadly Poison or Bouncing Flask and making the stacks grow with Catalyst, preferably its upgraded version that triples the enemy’s poison. You can also get the initial Poison stacks with Envenom if you have lots of 0-cost attacks or with Noxious Fumes if you have a good stall deck to survive a few turns. I recommend trying to stack at least 20 poison on The Heart before using Catalyst if that is your only source of big damage. That way, if you have two Catalyst+, you guarantee 180 damage per turn and just need to care about surviving.
  • If you’re going for face damage with attacks, use Horror to get those juicy 99 turns of Vulnerable. The Heart will never cleanse it, and you’ll get a free 50% damage boost the entire fight.
  • Add Phantasmal Killer to the Horror mix and you get an easy burst damage turn.
  • Don’t underestimate Caltrops. A single base version of this card can deal 45 damage to The Heart every time it uses Blood Shots. When upgraded, boost that to 75 damage. Caltrops is an attack card, essentially.
  • The Wrist Blade relic will help you with direct damage if you’re going for a Shiv build. Again, just be careful when using Shivs because Beat of Death can kill you.
  • The Snecko Skull will make your poison stacking just a little easier. It’s not mandatory, but it can save you a few card uses when stacking poison.
  • If you want to go for something flashy and niche, try some infinite discard combos like 2x Acrobatics and Tactician with a 0-cost attack. This will just be hard to set up during the run, and you will still need to solve not dying to Beat of Death.
  1. Can you block or resist at least 40(45) damage per turn?
  • Part of the ways to block this much damage is mitigating the damage as in item 4, with lots of Weak. All cards, potions, and relics listed there are also useful to block Echo damage.
  • Setting up extra Dexterity with one or two Footwork will help you a lot, so check your deck and try to pick it anytime during your run, starting late Act 1.
  • Wraith Form will save you from literally any damage you have to resist. It’s a prime card in lots of Silent runs and it’s useful against The Heart too.
  • Blur is Silent’s “we have Barricade at home”. It’s amazing if you’re going for a block-heavy deck or are caught by surprise with a handful of block cards in The Heart’s Buff turn. Also works perfectly with Burst for the double Blur stack.
  1. In a worst-case scenario, can you block or resist up to 240 damage (16×15) from Blood Shots if you can’t kill The Heart when it has 16 Strength on or before turn 14?

Two words: Wraith Form. But I’ll give you another four words: Ghost in a Jar.

  1. Do you rely on debuffs to kill enemies? If so, do you have enough debuff generation to burn through 2 stacks of Artifact reliably?

Silent is the Slay the Spire character that I almost always end up having a debuff-heavy deck, either with Poison or Weak cards. Because of that, it’s also pretty easy to remove Artifact from the Heart with her. To avoid over-explaining, I’ll just list ways to remove 2 Artifact that are card and energy-efficient.

  • Corpse Explosion and Crippling Cloud can be underwhelming against The Heart due to being AOE-focused skills, but they alone can remove 2 Artifact.
  • Bouncing Flask is a great Poison initiator (and scaling) card and will solve this problem alone.
  • Noxious Fumes will passively remove 1 Artifact per turn.
  • Envenom will turn any attack into a Poison card and effectively an Artifact-removal card. I’m considering this as free Artifact removal since you would play your attacks anyway. It makes multi-hit attacks like Dagger Spray and Glass Knife remove 2 Artifact on their own.

How to beat The Heart with Defect

Due to Defect’s orbs, the step zero that can help you solve many of the problems below is having a bunch of Focus and orb slot generation, which will increase the effectiveness of your orbs. 

  • The relic Data Disk, the Focus Potion, and the cards Defragment, Biased Cognition and even Consume (if you have orb slot generation) will give you Focus, leading to a great boost of damage and block with orbs.
  • Potion of Capacity, Capacitor or the relics Runic Capacitor (devs were not very creative with these names) and Inserter give you more orb slots to scale your power level. I also interpret the Gold-Plated Cables as a sort of invisible orb slot, since it triggers your rightmost orb an additional time, as if you had a copy of it in an additional slot.
  • The potion Essence of Darkness can be seen as an emergency button to evoke all your orbs while also replacing them with Dark, making your damage more consistent in the following turns. It’s a good potion to have.
  1. Do you have enough health or block generation to play cards while taking damage from Beat of Death?
  • Defect’s orbs let it gain block from orb-generating cards as long as they make you evoke Frost orbs. This essentially pays for the Beat of Death cost of these cards.
  • I love the guaranteed 10 block from Boot Sequence on turn one to help me set up any powers I need.
  • Steam Barrier, for zero energy, will get you the block buffer you need to play cards. Decent option for one or two deck cycles.
  • Emotion Chip makes taking one stance of Beat of Death per turn something you actually want, letting you trigger all your orb effects one time the next turn just for taking cheap damage.
  1. Can you protect against or get rid of debuffs?

Defect’s only way to defend against debuffs with its cards is Core Surge, which grants it 1 Artifact. I still prefer to save this Artifact to negate the Biased Cognition focus debuff, if I feel like I can survive turn two. Other than that, you’re relying on general cards and relics.

  1. Can you deal with Status cards?

Defect can exhaust Status with Recycle. Aside from that, I recommend having good card draw or manipulation like Hologram and Equilibrium to make sure you’re not starved of cards when you draw these Statuses.

  1. Can you deal with a buffed opponent?

Defect’s damage mitigation is poor, and your only viable debuff option against The Heart is an upgraded Go For the Eyes, which is also not that reliable if you can’t get it into your hand during attack turns.

  1. Can you deal 750(800) damage in 17 turns at most?
  • Ball Lightning and Tempest can help you set up Lightning and evoke them to burst the boss if you have some Focus. They will also increase your Thunder Strike value for a huge explosion of damage when needed.
  • Static Discharge is the perfect Heart counter against Blood Shots for Defect. If you take all the hits with the base version of the card, zero focus, and no orbs, you deal 96 damage back to The Heart. With its upgraded version, you deal 216 damage in that scenario, just by trading in some health.
  • Bullseye will help you scale Lightning and Dark orb damage, making it essential if your Focus generation is low and you rely a lot on orbs to get kills. Considering your deck can be quite big by the time of The Heart fight, which will make redrawing Bullseye difficult, I highly recommend upgrading it for three turns of boost instead of two.
  • If you’re running an attack deck, having an upgraded Beam Cell is a good option to boost your damage for two turns. Sunder and Streamline become even heavier hitters against Vulnerable opponents.
  • Meteor Strike is an amazing attack card if you have ways to play it. Make sure you either have reliable energy generation with relics and cards like Turbo or can reduce its cost with Snecko Eye, which is the dream scenario.
  • Dealing damage with Dark orbs can be tricky since getting them to a good damage value requires not cycling through your orbs, which is the key issue when fighting The Heart if your main source of block are Frost orbs. Still, if you have a big number of orb slots, like 7 or more, it should take you some time to evoke that Dark orb, letting it grow over turns. You can also make it grow faster with Darkness+ or go for the ultra-niche use of Recursion to evoke it and channel an exact copy of it back in your last slot. Since this is a very specific situation, I recommend not relying only on Darkness to deal damage against The Heart. Just use it as a bonus.
  1. Can you block or resist at least 40(45) damage per turn?

One of the best ways to block with Defect is to generate and evoke a bunch of Frost orbs with some Focus boost.

  • Glacier is your best bet and can win you the fight against The Heart. If you don’t have it, Coolheaded is a good alternative, and Cold Snap isn’t terrible if you have 4 or more focus.
  • Evoking the Frost orbs you generate is important. If you can do that with Glacier or Coolheaded, that’s even better because you’re replacing the Frost you lose when you evoke. Otherwise, the other orbs will still have use so evoking Frost is generally a good option, especially if The Heart is using Buff in the next turn, when you don’t need to block.
  • Leap is a fairly decent card for direct block, and I would take nine block for one energy any day if I need to survive.
  • Equilibrium will save you a lot of health while also letting you keep important cards in your hand for the next turn. Great card.
  • Force Field can easily be a 0-cost, 16 block card since late Defect decks tend to use a lot of Power cards.
  • Genetic Algorithm can be the best block card in the entire game if you build it up throughout the run. If you have room for it in your deck early, pick it and start using it.
  • Reinforced Body’s X cost lets you control how big you want your block to be, which is perfect in fights like this.
  • Buffer negates a full stance of Echo. Just be careful to not waste its effect by negating Beat of Death damage instead or using it against Blood Shots. Block first, Buffer second.
  1. In a worst-case scenario, can you block or resist up to 240 damage (16×15) from Blood Shots if you can’t kill The Heart when it has 16 Strength on or before turn 14?

That is a bit too much for Defect to handle effectively. You would need a good combination of a lot of Frost Orbs with a lot of Focus and maybe Weak too survive that. I recommend not relying on that and take an aggressive approach if you’re close to turn 14.

  1. Do you rely on debuffs to kill enemies? If so, do you have enough debuff generation to burn through 2 stacks of Artifact reliably?

Defect has no double debuff cards but also almost never relies on debuffs to kill The Heart. If you need Vulnerable and Lock-On for massive damage or Weak to survive, you probably want more debuff generation with Colorless cards or try to get a big stack of them on The Heart before turn 4.

How to beat The Heart with The Watcher

  1. Do you have enough health or block generation to play cards while taking damage from Beat of Death?
  • Prostrate will give you enough block to tank one instance of Beat of Death while also giving you Mantra to get closer to the much-desired Divinity stance.
  • I’ll consider Third Eye as a cheap block card against The Heart. Its block when unupgraded isn’t impressive, but it lets you thin out your deck with Scry, making it a valuable card.
  • Sanctity’s six block and two draw is great to let you cycle through your deck while protecting you for at least two Beat of Death hits later.
  • If you have a lot of Scry cards, Nirvana is a great option for a cheap, passive block.
  • Talk to the Hand is the perfect enabler of attack cards against Beat of Death, since it gives you at least two block per hit the opponent takes. Remember to clear The Heart’s Artifact before using this card.
  1. Can you protect against or get rid of debuffs?

The Watcher can only use Colorless cards and general relics to protect against The Heart’s debuffs.

  1. Can you deal with Status cards?

The Watcher’s way of getting rid of Status cards is by scrying them before drawing, making sure they don’t even show up in your hand. If you still draw them, the best you can do is to use net-positive card draw like Empty Mind, Inner Peace, and Scrawl to make up for the lost card draw.

  1. Can you deal with a buffed opponent?

The Watcher is almost as bad at debuffing The Heart as Defect, as she only has two options for doing so with Sash Whip and Wave of The Hand. Depending on your setup, the former can debuff The Heart long enough to make it Weak until you draw it again.

  1. Can you deal 750(800) damage in 17 turns at most?
  • Any card or combo that puts you in Wrath (Eruption, Tantrum, etc.) or Divinity stances (with Mantra generation cards like Devotion, Prostrate, and Worship) will push you close to the Invincible damage limit. Abuse the two stances for it.
    • Make sure you can exit Wrath if you are being hit that turn, either by entering other stances, especially with Fear no Evil, or using “Empty” cards (Body, Fist, and Mind).
    • Flurry of Blows is cheap damage that can build up quite nicely if your key strategy is shifting stances constantly. Just check your block and health because dealing cheap damage against The Heart when you have low block generation can be detrimental.
    • Apply the same logic to Weave, but for Scry cards.
  • Getting free Smites in your hand every turn with Battle Hymn is great to make sure The Heart fight doesn’t go too long. The same goes for Carve Reality.
  • In the realm of slow but decent damage cards, there is Reach Heaven solving your offensive problems by generating Through Violence and Sands of Time becoming a 0-cost card in four turns. You will suffer in the early turns to collect your rewards in the late game, so make sure you have good defensive options while settings them up.
  • Using Crush Joints to leave The Heart vulnerable is a good option for damage scaling. You can easily trigger its effect if you use a Miracle first.
  • Indignation is also a good Vulnerable resource on a Wrath-heavy deck.
  • Ambrosia potion will put in Divinity stance instantly, turning it into a big damage resource. Stance Potion can put you in Wrath, effectively making it a damage potion.
  • If your big damage are multi-hit cards like Ragnarok and Tantrum, Wreath of Flame is amazing since it increases these cards’ base damage per hit by 5, which means Wrath will make it 10 more damage per hit and Divinity will make it 15, letting you use a huge 150-damage Ragnarok while in Divinity or even 225 damage if The Heart is Vulnerable.
  • I only recommend running Alpha for Omega damage if you have a reliable way to get these cards and Beta out of your deck quickly, if you have good damage mitigation and block, and maybe even Omniscience to play Omega twice. Otherwise, don’t rely on them too much.
  • Blasphemy is a tricky card but it can help you a lot. What the card means by “Die next turn” is that by the start of your next turn, you will lose HP equal to your total remaining health, meaning blocking is useless. However, a Buffer stack from Fossilized Helix or Intangible from Incense Burner or Apparition will let you survive.
    • Note that it kills you at the start of your next turn. So if you use Blasphemy and have only one intangible stack, or if you lose your Buffer to damage after you end your turn, you will still die. That means you effectively need to conserve your Buffer or have at least 2 Intangible.
  • Killing The Heart using Judgement will morally give you extra points for style and probably some karma on Reddit if you share a screenshot of it.
  1. Can you block or resist at least 40(45) damage per turn?
  • Mental Fortress is one of The Watcher’s prime block sources, especially when upgraded for 6 block per stance change. Gaining block whenever you enter any stance (including neutral) makes you gain block even with some attacks. If you have a good combination of Calm, Wrath, and draw cards, you can get huge block numbers while playing little to no direct block cards.
  • Talk to the Hand is the other great block card for The Watcher, especially when upgraded or used multiple times with two copies or Omniscience. It turns multi-hit cards like Tantrum and Ragnarok into big block generators. Just be careful since its effect is a debuff, so remove The Heart’s Artifact before using it to not be denied.
  • Halt can be a great block card when you’re in Wrath. The best way to use this card is to enter Wrath, use the card, and leave Wrath before the turn is over. This way, you get the extra Wrath block but deny the double damage debuff from the stance.
  • You can apply the Halt play logic to Wallop. Use Wrath, use Wallop to deal at least 18 damage, and leave Wrath to retain the heavy block you gained.
  • Protect is a decent card to have since it stays in your hand and you can use it in the turn you need it. It’s more impactful with some Dexterity and when upgraded. The same logic applies to Safety you generate from Deceive Reality.
  • Fasting can be incredibly useful if you use it when you have Artifact or can cleanse its debuff with Orange Pellets. The three dexterity can be just what you need to make survival an easy task.
  • Like Water is a good power to get you some extra block from defensive turns when in Calm. 
  • While Perseverance may look like a good big block card, it won’t make it alone. The Heart outscales it quite fast. By turn 14, the most it can do is block for 46 at zero Dexterity while The Heart can be hitting you for 240 with Blood Shots.
  • Spirit Shield can be great when used with big draw cards, letting you block for a maximum of 27 unupgraded.
  • Duality is a funny relic to use against The Heart. It gives you Dexterity when you use an Attack, which means you’re taking Beat of Death damage to recover that block in the future. It’s useful, but not essential.
  • Cloak Clasp relic may be a cheap block sometimes, but any free block against The Heart is good. If you have lots of cards Retained, that block every turn can actually save you.
  1. In a worst-case scenario, can you block or resist up to 240 damage (16×15) from Blood Shots if you can’t kill The Heart when it has 16 Strength on or before turn 14?

That’s a tough one for The Watcher. If you have a consistent and near-infinite Calm-Wrath loop with card draw and any combination of Mental Fortress and Talk to the Hand, maybe. I wouldn’t rely too much on that, though. The Watcher will rarely need to take the fight that long because of how easy it is to deal damage with her.

  1. Do you rely on debuffs to kill enemies? If so, do you have enough debuff generation to burn through 2 stacks of Artifact reliably?

The Watcher just needs herself to explode The Heart, but she may rely on Talk to the Hand, which is a debuff, to generate block. In this case, it’s easier to have a good way to use Talk to the Hand by turn four with card draw and Omniscience. If you don’t trust these two methods, I recommend getting Wave of The Hand for multi-Weak applications and burning these Artifacts in a single turn.

What runs that beat The Heart look like

Below you will find my runs where I took down the Heart with each of the four characters. Try and analyze them as an exercise. How many of the eight points do these decks tick? If any of the points are not covered, why was it not necessary to solve that problem?

Ironclad runs

Silent runs

Defect runs

The Watcher runs

About the author

I have played Slay the Spire since 2020 and have logged over 800 hours in the game. I have beaten The Heart on Ascension 20 with all characters multiple times, including mod characters like Wanderer and Hermit. I also have the Keys tattooed on my right arm because I love this game a little bit.

I know the Slay the Spire community, so I’m sure some people will read this guide and think since I’m not as proficient as Jorbs, Baalorlord, or TerrenceMHS, this guide isn’t good. That also means this guide is probably not for you and you’re looking for an even deeper conversation about the game. I recommend going to their YouTube channels and getting an even deeper look at successful A20 Heart runs, since they actually play this game for a living, unlike myself. You would actually be surprised how little time you have to play when you’re working with games.

Now you go slay the spire. And so shall I.

- This article was updated on May 31st, 2023

About The Author

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Bhernardo is a senior editorial strategist and has been working in the gaming industry for over 8 years. He loves Slay the Spire so much his first tattoo is of the game's Keys.