Patch 1.2.0.1: full notes
Patch 1.2.0.1 raised the mutagen drop rate from 2% to 3%, capped baby Trex speed at 95% of the target player's max speed, stopped mutations copying the Survivor's shop effect, and fixed a co-op crate crash plus several shop and Codex bugs.
Patch 1.2.0.1 landed on 3 November 2026, one day after launch. The developers framed it plainly: "We are focusing on bug fixes for now... we intend to address balancing in the coming days after taking the time to read your feedback."
So this is a bugfix patch with three balance changes, not a rebalance. Everything in it is listed below, reorganised by what it changes rather than by the order it appeared in the post.
Balance: three changes
| Change | Before | After | Why it matters |
|---|---|---|---|
| Mutagen drop chance | 2% base | 3% base | Mutation path advances roughly 50% faster |
| Mutations copying the Survivor's shop effect | Allowed | Blocked | A Mutation run can no longer duplicate a shop penalty |
| Baby Trex speed | Uncapped | 95% of the target player's max speed | A pursuit enemy can no longer outrun a player at full speed |
The mutagen change is the one most players will feel. The baby Trex cap is the one that fixes a fight that had no answer: if a creature can move faster than you, kiting stops working, and the only counterplay left is killing it before it reaches you.
Fixes: seven items
| Fix | What was broken | What it means in play |
|---|---|---|
| Co-op crate crash | Several players choosing a crate reward at the same time while playing the Survivor crashed the game | Co-op Survivor runs are stable |
| Hourglass shop refresh | Buying the Hourglass did not update the shop correctly: the Endless button and boss icon showed when the next wave was not wave 20, and upcoming wave icons did not match the real next wave | The shop now tells you the truth about what is coming |
| Wave 19 shop layout | The Go button was cut off at the bottom of the screen; boss icon missing from the Endless and Go buttons | Wave 19 is playable without scrolling a hidden button |
| Co-op mecha parts counter | The counter pushed another player's column off screen | It now sits next to the weapons count |
| Co-op mechanized weapon stats | Stat choices overflowed onto the price and the next player's column | Readable in co-op Mecha runs |
| Brachiosaurus Codex entry | The creature and its foot did not display correctly | Codex completion is accurate |
| Title screen logos | Logo position wrong on the New Dawn and All Pain No Gain screens | Cosmetic, fixed |
Two of those deserve a note. The wave 19 fix is not cosmetic: a Go button that is cut off at the bottom of the screen is a run-ending bug if you cannot scroll to it. And the Hourglass fix explains a class of confusion players reported on launch day, where the shop appeared to promise a boss that was not coming.
Translations: three fixes
- "Mechanize" is now translated in all languages.
- Spanish: fixed the wording of stat modification effects and the Spoon's burning crit description.
- French: fixed missing accents on "Mécaniser".
The Mechanize line is the interesting one, because it confirms the verb is used in the game's UI, not just in patch notes. If you play in a non-English language and the Mecha path looked half-translated on launch day, this is why.
Missing from 1.2.0.1
No new content, no character nerfs, no weapon damage changes, no changes to the Nightmare difficulty itself. The Nightmare rebalance happened in the free 1.2.0.0 update the day before, and it is covered separately on the Nightmare page.
There is also no fix listed for the Jungle's boss roster or wave structure, because nothing was reported broken there. The patch is narrow on purpose.
Should you restart your run
No. Nothing in 1.2.0.1 changes a run in progress in a way that requires a restart. The mutagen rate applies to future drops, the Trex cap applies to future chases, and the shop fixes are UI.
The one exception is a co-op Survivor run that crashed before the patch: that save is what it is, and the crash is fixed for future runs rather than repaired retroactively.
Reading a patch like this
Three habits make patch notes useful rather than noise.
Sort by category. Balance changes alter what you should do; fixes alter what the game does. This patch has three of the first and seven of the second, which is a normal ratio for a day-one patch.
Look for the notes that imply a mechanic. "Mutations can no longer copy the Survivor's effect" is a fix, but it also documents that the Survivor has a shop constraint and that Mutation reads character traits. Patch notes are often the only public documentation a mechanic gets.
Check the build number before trusting a guide. This site is written against 1.2.0.1. Any guide dated 2 November 2026 is describing the 2% mutagen build, and the difference is large enough to change advice.
For the free update that shipped the day before, see Item Set and Nightmare changes.
Which build this is
Everything above is 1.2.0.1, released 3 November 2026. If your game shows 1.2.0.0, the three balance changes in this patch have not reached you yet, and the mutagen rate is still 2%.
Checked 2026-11-04 against the 1.2.0.1 build.