A player noticed something felt off. Not in a vague, gut-feeling way, but in a "I'm going to spend eight hours documenting this until someone believes me" way. That player, known as tckmn on the Slay the Spire subreddit, published what the developers themselves called an "eight-hour descent into madness" , a detailed breakdown proving that Slay the Spire 2 had a genuine RNG bug baked into one of its most consequential early decisions. Mega Crit listened, and the fix is now live.
The bug that made Neow's Bones feel rigged
Here's the thing about RNG bugs: they're notoriously hard to prove because human brains are terrible at evaluating randomness. Miss a 95% hit in XCOM once and your brain files it as a conspiracy. So when players suspected that Neow's Bones, a starting relic option that trades two relics for a curse, was handing out the punishing Debt curse more often than it should in certain conditions, it was easy to dismiss.
Tckmn didn't dismiss it. After eight hours of investigation, the findings were clear: starting a run in the Underdocks made Neow's Bones 54% likely to hand you the Debt curse specifically. That's not bad luck. That's a broken system.
The root cause came down to how the game handles pseudo-random number generators (PRNGs). Slay the Spire 2 uses multiple PRNGs fed different seed values, which should make their outputs completely independent. The problem was that the decimal values governing which Act 1 area you started in happened to correlate directly with the values determining your Neow's Bones curse. If your act roll landed above 0.5 (putting you in the Underdocks), the curse roll was highly likely to land below 0.5, cutting the potential curse pool in half and dramatically inflating Debt's odds.
Mega Crit has since overhauled the seeding system to eliminate this correlation. The patch notes sign off on it with a note that's equal parts apologetic and amusing: “Rest assured that your suffering is now truly random.”
Balance changes, a boss retirement, and a new Act 3 threat
The RNG fix is the headline, but the patch covers a lot of ground. Balance adjustments hit several cards, with the Regent seeing the most significant changes. Monarch's Gaze got a bump upward, while Reflect took a slight nerf. The key here is that Mega Crit has been clear these passes are iterative, not final verdicts, so card values shifting around is expected territory for an early access title.
The bigger news for endgame players is the Act 3 boss situation. The Doormaker has been removed. The developers were candid about why: while the fight had interesting micro-decisions, it crossed a complexity threshold Mega Crit wasn't happy with and had lingering design issues that weren't worth patching around. Starting fresh was the cleaner call.
In his place arrives The Aeonglass, a new Act 3 boss built around a DPS race. The fight pumps Wither curses into your hand that deal damage to you directly, and the boss ramps those curses rapidly by upgrading them over time. Players who like to play slow and build up resources will feel the pressure immediately.
What this means for players right now
For most players, the practical impact of the PRNG fix is simple: Neow's Bones is now a fairer choice. If you were avoiding it because runs out of the Underdocks felt punishing, that correlation is gone. The starting relic trade-off should now play out the way it was designed to, with curse selection being genuinely unpredictable regardless of which Act 1 area you land in.
The Doormaker's removal also means Act 3 prep changes. Builds that were tuned specifically to handle his fight mechanics need rethinking for the Aeonglass, which rewards aggression and punishes slow, defensive setups that let Wither curses stack up.
What most players miss in patches like this is how much the balance changes ripple through character strategies beyond the obvious card tweaks. If you're working through higher Ascension levels, the Slay the Spire 2 strategy guides are worth checking for updated build paths given the Regent and Reflect adjustments. For Ironclad players specifically, the Ironclad builds and card guide covers how to structure your deck around the current card values.
