Slay the Spire 2 adds 15 co-op multiplayer cards across all five classes

Slay the Spire 2 just dropped a hefty co-op update on its Steam beta branch, adding 15 new multiplayer-focused cards spread across all five classes — Ironclad, Silent, Regent, Necrobinder, and Defect — plus one new colourless card, a handful of reworks, and a nerf to enemy Block scaling in two-player matches.

The Ironclad's standout is Midnight, a rare attack that hits for 99 damage (120 upgraded) but costs 12 energy — reduced by one for every card any player Exhausts during the fight. Blaze hands another player 5 Strength, and Outrage deals 9 damage for zero energy while copying itself into every other player's discard pile. Silent gets Blade Symphony, which drops 2 shivs into every ally's hand, plus Concoct to spread poison through a teammate's attacks and Fade, a retainable card granting 6 Dexterity to another player for the turn. Regent's Plot lets everyone draw 2 extra cards next turn, while Constellation gives a target player energy, a card, and 9 Block. Necrobinder picks up Underworld, which applies Doom based on how much damage allies deal, and Cacophony, which hits a random enemy for 66 damage per every 33 cards drawn collectively. Defect's Imitation Learning copies a target player's next two power cards, and One For All adds three damage to every zero-cost attack card across the whole team. Then there's The Ball — a colourless card that bounces to a random ally's pile after each play and permanently increases its own damage by 15 for the rest of combat. It is, by all accounts, a menace.

Slay the Spire 2 has been in Early Access since January 2025, developed by Mega Crit — the two-person studio behind the original Slay the Spire, which became one of the most influential roguelite deckbuilders ever made. The sequel introduced co-op multiplayer as a core feature, something the original never had, and these cards are clearly designed to reward coordination: shared shivs, bouncing damage tools, and cross-player buff chains all push teams toward synergy rather than parallel solo runs.

The update is live now on the Steam beta branch, so it hasn't hit the main Early Access build yet. Given how much raw power is packed into some of these cards — Midnight's 99-damage ceiling, Cacophony's scaling — expect plenty of community testing and probably some follow-up balance tweaks before this lands in the stable branch.