Slay The Spire’s hidden final boss can only be unlocked by mastering the three base characters.

Each carries one of the three keys you’re gonna wanna progress into the last act.

Slay The Spire is a fun rogue-like game that utilizes cards.

Victory art of the Ironclad in Slay The Spire

Like most rogue-like games it is hard, so confirm to note these helpful tips.

Knowing how to prepare for this final boss can save you some heartache on a lost run.

Each one unlocks a different key to be collected in future runs.

Collage image with the soldier and Silent characters posed with weapons drawn in front of a backdrop

To challenge the Heart, you’ll need tocollect all three keys in a single run.

The Watcher does not unlock a key but can collect the keys unlocked by the other characters.

Once all three keys are unlocked, there will be anemblem next to your usernamein the top left.

The Ironclad fighting the Collector in a boss fight

The Ruby Key

The Ironclad’s key is the simplest to collect once unlocked.

When youreach a campfire,you will have a new option, to’recall'.

Meditating at the campfire gives you thered keyatthe cost of not resting or upgrading a card.

Slay The Spire’s Campfire screen with the recall option to gain the red key

The Sapphire Key

The Defect’s keyreplaces the loot of non-boss chests.

Taking the chest loot will mean theblue key will be offered again on the next chest.

Items that override chest loot have an impact on the blue key.

Slay The Spire’s Sapphire Key being offered as an alternative to the relics in a chest.

The Matryoshka causes the chest to have two relics.

Only one of them will be linked to the key, and the other can be safely looted.

Check your map; one of the elite encounters of each Act will have aflame decalon it.

Slay The Spire map showing the Elite encounter with the emerald key

The best act to get the Emerald Key in is dependent on the character and deck you’re using.

The Silent’s slower buildup and combo playstyles make them very effective against some of the Act Three elites.

In general,avoid Act Two elites entirelyunless your deck is especially powerful at the end of Act One.

The Three Keys unlocking the fourth act in Slay The Spire

Act Four

Act four has no normal encounters or events available.

You willalways encounter the same sequenceof map nodes.

You’ll have theSurrounded Debuffwhile both enemies are alive, a unique mechanic to this fight.

Indie Games

Theenemy you turned your back on(by attacking the other) willdeal 50 percent bonus damage.

The Heart’s Beat Of Death passivedeals one damage every time you play a card.

TheMedical Kit shop reliccan exhaust unplayable status cards.

Slay the Spire

TheOrnamental Fan relic, Afterimage power and Rage skillcan produce enough blocks to offset Beat of Death.

Ramp Decks (Demon Form, Omega, Barricade)

The Heart applies buffs to itself at three-turn intervals.

After its first turn, inflicting debuffs and statuses on you, it will rotate through three moves.

They also let youdelete or avoid cards that are too slow or ineffectiveto help in the boss fight.

Each character has a unique victory screen for defeating the Heart, including the Watcher.