Dice and rerolls
A reward screen you dislike used to be a take-it-or-leave-it moment. Patch 0.6.39 added a way to ask for a different set, and within days the forum had a run of threads about what happens when you do.
One reroll, two outcomes
What the developers say Dice are
The patch notes put it in one line: “Added ‘Dice’, which can be collected to allow you to reroll certain card choices!” and give the reason, “Added this to smooth out some of the frustration players raised with RNG.” (both in Steam announcement: Shroom Patch Notes: 0.6.39) They were also upfront that it is unfinished. The same paragraph warns that it may show up on camp encounters where it is not meant to, and that “you can’t re-roll in all situations we would like you to. This will be improved over time.”
That is everything official. How many Dice you can hold, which cards drop them and what a reroll costs are not in the notes. The one player who wrote the steps down says you “Get a dice card and use it to gain reroll” (in Steam discussion: Rewards vanish when using reroll, gets softlocked), so a die reaches you as a card, and another says they had “a die (re-rolls) from earlier”, which suggests they carry over between screens (in Steam discussion: Softlock: Reroll, Dig, Papers).

The reward screen that locks
Every report starts on a screen like the one above, where cards are offered above a No Thanks button. What differs is where the player was and what they did just before. Four threads give five situations:
| Where it happened | What the player says |
|---|---|
| Janitor run, an ordinary reward | “when I reroll all three cards disappear and the ‘No Thanks’ becomes inactive”, and a second player in the thread had the same (in Steam discussion: Rerolling bugs |
| A data station, and other stations | Rerolling can hand you the wrong station, a vending machine where a data station should be, or leave you with no rerolls at all; the fix they found: “Have to return to main menu and try room again.” (same thread: Steam discussion: Rerolling bugs) |
| After clearing gloom off some vials | Rewards vanish instead of being replaced; the three steps are to use a dice card, banish the gloom over the vials with a reveal card, then reroll (in Steam discussion: Rewards vanish when using reroll, gets softlocked |
| Digging a pile of papers | No cards appear, the back button does nothing, and another reroll gives the same. A reply hit the same on a hanging figure they revealed, and another after revealing a heart-shaped shadow (in Steam discussion: Softlock: Reroll, Dig, Papers |
| A Facility campground | After revealing an object twice to get a choice of two cards, a reroll showed no cards, “hardlocking me in that selection screen” (in Steam discussion: Hardlock in facility campground |
A fifth thread adds a smaller symptom: rerolls that do not give new options while the old ones disappear, and a counter that “only showed five rerolls available, not six”, again from a Janitor run (in Steam discussion: Reroll is broken). Two of the reports name the Janitor and the rest name no character, so the safe reading is that it has hit more than one kind of reward, not one particular screen.
Getting unstuck
Everyone who got out did the same thing: quit to the main menu and reload the run. It costs you the room. One player says re-entering “reset the entire area” and that the papers they had dug were no longer there, with a hanging figure in their place (in Steam discussion: Softlock: Reroll, Dig, Papers), and another lost the layout of the campsite: reloading “also rerolled the configuration of the campsite” (in Steam discussion: Hardlock in facility campground). In these two reports, reloading did not keep the area or campsite as it was.
One player took the lesson: “gonna be careful about rerolls now” (in Steam discussion: Softlock: Reroll, Dig, Papers). If you have a die and the reward on screen is one you can live with, take it. If you do use one, expect to do it on a screen you are prepared to redo.
Where this fits
Dice sit next to the other 0.6.39 changes: cleaning-card text rewritten, Melty and Gunk Pile made temporary, and a long list of card retunes. The Janitor part of that list is on the Janitor guide, the camp building changes are on camp structures, and how card text and the two decks work is on cards and the two decks. If a reroll locked you on the second map, the Facility page has the other problems players hit there.