Slay The Spire 2 Caps HP at Nearly a Billion, Crushes Crashes, and Rebuilds Mod Support

Mega Crit has pushed a substantial update to Slay The Spire 2 through the game's opt-in public-beta branch on Steam, targeting a long list of crash bugs, multiplayer desync issues, softlocks, and localization problems. The patch also introduces new card portrait art, adjusts several balance values, and completely restructures how the game handles mods. Players can access it by right-clicking Slay The Spire 2 in their Steam Library, selecting Properties, then navigating to Game Versions & Betas and switching to the public-beta branch. A full public release is scheduled to follow once stability is confirmed.

The balance section of the update is brief but striking. Players, enemies, and pets can no longer have their HP increased above 999,999,999. That a hard ceiling on a ten-digit number needed adding to a deckbuilder at all tells you something about how far players have pushed the game's systems in early access. Beyond that single cap, the Ironclad's Hellraiser power has been corrected so it no longer plays Strikes when no valid targets exist. Two relics — Fairy in a Bottle and Lizard Tail — now function correctly when a player's maximum HP sits at exactly 1, restoring their healing behavior in edge-case runs. Tezcatara's Brightest Flame card can no longer reduce a player's maximum HP below 1.

Three cards received new portrait art in this update: Feeding Frenzy, Sloth, and Waste Away. An icon for the Murderous run modifier was also added. The placeholder art still present throughout Slay The Spire 2 has drawn attention since launch — not for being unpolished, but because its handmade, unfinished quality has become part of the game's early access identity. The concern, raised publicly around the game, is whether any of it was generated by AI tools. No confirmation either way has come from Mega Crit.

On the crash side, the patch resolves a failure that occurred when players interacted with potions during combat transitions, a crash tied to syncing cloud saves on Windows, and one triggered specifically when selecting the Ironclad character on systems running a Turkish locale. A rare save data loss issue on Windows — occurring when power was cut during a save operation — has also been addressed. Navigating away from menus too quickly no longer causes a crash either.

Several softlocks have been closed. The game previously had the potential to lock up when auto-played cards triggered grid or card selection screens. Players can no longer get permanently stuck in the Room Full of Cheese event or the Jungle Maze Adventure event after dying. The Lasting Candy relic no longer causes a softlock when triggered from the fixed tutorial card rewards.

Multiplayer received its own cluster of targeted fixes. A desync between host and client, generating different maps from the same random seed, has been corrected, which is a foundational issue for cooperative play. The Doormaker's Door HP now scales correctly after the Doormaker escapes during a run. Players can no longer get stuck unable to end their turn after dying while the Whispering Earring relic is autoplaying their cards. Getting permanently locked at an empty chest — another reported multiplayer issue — has been resolved. A crash when returning to the map after loading a multiplayer save has been patched out, along with a state divergence tied to playing Huddle Up during another player's card selection phase.

The update also addresses a problem where the map changed after reconnecting when the Big Game Hunter modifier was active, or when players carried the Treasure Map and Golden Compass relics. A softlock caused by a player dying with cards still in hand has been removed. Potion Belt and Alchemical Coffer relics together no longer lock up the game.

Localization fixes span Italian, Russian, Simplified Chinese, Turkish, German, Spanish, and Polish. Card descriptions for Call of the Void, Coolheaded, Fuel, and Ice Lance were displaying raw template text in Russian rather than translated strings. Run histories viewed in Russian showed incorrect data when the player had chosen The Defect character. Specific card and event text errors were resolved in Portuguese, Castilian Spanish, German, French, and Korean. Font rendering was adjusted in Japanese, Korean, Russian, Thai, and Simplified Chinese — the Japanese font specifically was made slightly smaller and raised to improve vertical centering.

The modding overhaul is the most technically significant part of the patch. The mod_manifest.json file has been moved outside of the PCK container. Each mod must now ship with an additional file named after its mod ID in JSON format, following the updated ModManifest structure. Crucially, a PCK file is no longer required for every mod — the JSON file alone is sufficient to declare a mod, provided it specifies whether a PCK or DLL is included. The settings.save file now records a full list of all mods loaded during the last game run, and reordering that list directly affects load order. Mods can declare dependencies within their manifest file; if the load order stored in settings.save conflicts with those dependencies, the game forces a re-sort automatically. A new affects_gameplay field has been added to the manifest — when set to false, the mod will not be checked against the host's mod list in a multiplayer session. The update also brings 0Harmony and MonoMod up to support mac arm64, eliminating the previous requirement to manually overwrite those files.

I think the modding changes here carry more long-term weight than the bug list — a cleaner manifest system and native mac arm64 support lower the barrier for mod developers meaningfully, which matters for a game where community content drives replay value.

Slay The Spire 2 reached a peak of nearly 570,000 concurrent players on Steam shortly after its early access launch, placing it among the platform's most-played titles at that moment. I still find it remarkable that a card game held a top-three position on Steam by concurrent player count for multiple days — it probably says something durable about the health of the indie scene and how seriously both players and AA and AAA publishers should be taking it. The full patch notes on Steam cover additional fixes not detailed here, including controller navigation corrections, dropdown menu behavior in settings, and the share button localization fix in the stats screen.

Here’s original patch notes from the Slay The Spire 2 team's post on Steam:

BALANCE:

• Players, enemies, and pets can no longer have their HP increased above 999,999,999

ART:

• Add icon for Murderous run modifier
• Added portrait art for the following cards:
• Feeding Frenzy
• Sloth
• Waste Away

BUG FIXES:

General:

• Pressing B on controller while focused on a dropdown menu no longer also closes the settings screen
• Fixed crash when interacting with potions during combat transitions
• Fixed crash when syncing cloud saves on Windows
• Fixed rare save data loss on Windows when power is lost during a save
• Fixed crash when quickly navigating away from menus
• Fixed dev console failing to match commands on non-English system locales
• Fixed potential softlock when auto-played cards trigger grid or card selection
• Fixed state divergence related to discarding potions too soon after combat ends
• Fixed being able to "peek" in card screens outside of combat
• Fixed closing the settings menu while a dropdown is open not also closing the dropdown
• Fixed navigating down the dropdown items causing the settings to scroll down
• Fixed softlock when auto-played cards triggered card selection

Ironclad:

• Fixed Hellraiser power playing Strikes if there are no valid targets

Potions & Relics:

• Fixed Fairy in a Bottle and Lizard Tail relics not healing you when your Max HP is 1
• Fixed Massive Scroll relic description saying that it can only give you Colorless multiplayer cards
• Fixed softlock if you proc Lasting Candy relic from the fixed tutorial card rewards
• Fixed Hand Drill relic applying Vulnerable to the player if Burn card breaks their block

Enemies:

• Fixed missing Kaiser Crab boss death VFX
• Fixed Kaiser Crab face animation not looping after a claw takes damage
• Fixed the word "Stunned" not appearing when Rock Bowlbug does its stunned move

Ancients:

• Fixed Tezcatara's Brightest Flame card being able to decrease your Max HP to less than 1

Events:

• Fixed softlock when dying in the Jungle Maze Adventure event
• Fixed softlock if you die in the Room Full of Cheese event

Multiplayer:

• Fixed softlock when any player has Potion Belt and Alchemical Coffer relics
• Fixed being unable to navigate via controller if you unready yourself in lobby
• Fixed players being unable to end their turn when they die while the Whispering Earring relic autoplays their cards
• Fixed Doormaker's Door HP not scaling correctly after the Doormaker escapes
• Fixed softlock when queueing a potion to be thrown after the enemy would die
• Fixed crash when returning to the map after loading a multiplayer save
• Fixed host and client sometimes generating different maps from the same seed
• Fixed map changing after reconnect with the Big Game Hunter modifier or Treasure Map and Golden Compass relics
• Fixed softlock caused by a player dying with cards in their hand
• Fixed state divergence related to playing Huddle Up during another player's card selection
• Fixed timing-related state divergence occurring at the end of a combat
• Fixed rare instances of getting stuck at an empty chest

Localization:

• Fixed crash when selecting Ironclad on Turkish locale systems
• Fixed Russian card descriptions showing raw template text for Call of the Void, Coolheaded, Fuel, and Ice Lance cards
• Fixed an issue when viewing run histories in Russian where the player played as The Defect
• Fixed an issue with Buffer+ card's description when playing in Portuguese
• Fixed an issue with Call of the Void card's hovertips when playing in Castilian Spanish
• Fixed an issue with Colossus card's hovertips when playing in German
• Fixed an issue with the "Accept" option in The Trial event when playing in French
• Fixed an issue with the "Violence" option in the Tinker Time event when playing in Korean

LOCALIZATION:

• Added more translated text for various languages
• Fixed translation and formatting errors for: Italian, Russian, Simplified Chinese, Turkish, German, Spanish, Polish
• Adjusted Japanese font to be rendered slightly smaller and raised to improve vertical centering
• Improved Korean font spacing
• Improved Russian and Thai font rendering
• Improved the look of Simplified Chinese font
• Share button in stats screen now utilizes correct localized string

MODDING:

• mod_manifest.json has been moved outside of the PCK. All mods should now ship with an additional file named <mod_id>.json — see ModManifest for the new JSON structure
• PCK is no longer required for all mods. Json is the only file that is required to declare a mod. The json must declare whether the mod includes a pck/dll file
• settings.save now includes a list of all mods that were loaded in the last game run. Reordering this list affects load order
• Mods may declare dependencies in the manifest. If settings.save declares a load order incompatible with the listed dependencies, then a re-sort is forced
• Added affects_gameplay field to mod manifest. If false, then the mod will not be checked against the host's mods in a multiplayer game
• Updated 0Harmony/MonoMod to support mac arm64. Manually overwriting it should no longer be required

Read also, a full beginner's guide to Slay The Spire 2 covers how to get started, how characters work, and how relics function — including details on the co-op mode supporting up to four players, which is one of the major additions over the 2019 original.