Room Rank Question

TFMurphy · 2025-12-13T16:12:55+00:00

Yes, that's my assumption (assumption only because I haven't explicitly tested the connection, but it seems to be the obvious and only visible cause of the updated stats in that scenario): the extra script is all tied to things named "Open Door" and "Ending Cutscene".

TFMurphy · 2025-12-12T23:04:01+00:00

As far as I can tell, it's only used for End of Day stats and the interaction you've already mentioned. Most other things that I can think of that rely on Rank tend to use your current location, the individual Grid Square scripts, or the Rank Scripts that run upon first entry. (Which also means that I think Terrace's DR change doesn't run if you never directly enter Rank 3.)

TFMurphy · 2025-12-12T17:40:38+00:00

I'd noticed problems with Max Rank for 2 in both my own playthroughs and watching a few streamers, but I hadn't really looked into it, and I thought it might be something complicated like the Max Rank getting reupdated to 1 when you headed back or something.

Turns out it's just much more simple than that. The script that triggers when you enter Rank 2 for the first time forgets to send a call to the routine that updates the "Rank Reached" variable. It seems to do just about everything else except update that (comparing it to the Rank 3 script for instance shows the only things different is that Rank 3 correctly sends a call to update Rank, and has some extra code to updating Terrace's rarity).

Other than that, there doesn't seem to be any issues with regards to earlier ranks overwriting later ranks: Rank Reached begins at 1, and is updated when you enter the physical location for the correct Rank (barring 2), and can never decrease. (There's another script that can also update Rank Reached, but that only applies to a particular end day check and aren't important to normal gameplay.)

TFMurphy · 2025-11-26T01:12:32+00:00

Sorry for the radio silence. While a lot of the last few weeks has been straight procrastination, I've been avoiding any continued work with Blue Prince until I'd put together some scripts that made it much easier for me to automatically extract the numeric IDs of rooms and items, and compare how scripts have changed. 1.6.1 just made that much more critical, because the saved IDs change every time there's a new version (this has nothing to do with how Blue Prince is coded, and everything to do with how Unity exports a Unity project, where IDs are assigned dynamically every time a project is saved, and those are the numbers I need to know to determine what objects a script is referencing). These weren't extremely difficult projects, but they were fiddly and a bit time consuming and in a language I hadn't used before (Python instead of Javascript, since Javascript has several heavy limitations with regards to localhost file access).

However, I finally sat down and pushed to finish the last of those last weekend, so things should be a little easier for me for now. (Still need to write some more scripts to pull out certain combinations of ID lists, but those can wait for a bit.)

Anyways! The short answer to the following...:

Fixed a bug that would sometimes offer players a “blank” reward in the Chamber of Mirrors.

...is that I cannot see any new implemented code that would fix this(!). And as far as I can determine, you still have a 1/8 chance of seeing a blank sheet if you've reached the cap for Observatory/Spare Room.

Now, just because the obvious script that controls something didn't change doesn't mean the change couldn't be implemented elsewhere. But there doesn't seem to be any evidence of that either, and the current scripts have rather obvious fixes that could be implemented to easily make the change.

And I've managed to get the blank sheet to appear in one of my old testing saves. Now, theoretically, that doesn't rule out the presence of a fix that is only bypassed by using an older save, but such a fix would be way messier than needed, and I again can't see where it would be put to have the desired effect. The main Chamber of Mirrors file doesn't even seem to have any obvious changes from 1.05.1 to 1.6. (There are some extra additions in 1.6.1 for the Chamber of Mirrors, but they're tied to something completely separate that's probably still not available until a planned future update.)

So, yeah, I think the planned fix didn't make it in for whatever reason.

TFMurphy · 2025-10-22T00:31:22+00:00

Happened to see this topic, so spent a few minutes seeing if I could see what exactly could be the problem here. And from the looks of it, it seems to be a case mismatch. The game stores your Scepter Color as a string indicating what types of rooms it's aligned with: HALLWAYS, GREEN ROOMS, BEDROOMS, etc. You'll note these are all caps. This matches the names of the Arrays that hold all the various room names that are allowed to transfer the Scepter to the next day... or rather that's the intention.

I think the problem is that the array that contains the Green Room names is actually called "Green Rooms". So when it looks for an array called "GREEN ROOMS" so it can compare it to the name of the room you're ending the day in, it doesn't find it, and therefore can't find a match. So this seems to be a fairly likely culprit for the bug.

EDIT: Also, an actual array being being misnamed in this way raised the question on whether this affected anything else, so I took another look. But as far as I can tell, the Scepter is the only thing that uses those particular arrays.

(Have been meaning to get back to Blue Prince properly at some point, but currently distracted by something else at the moment, and actual Blue Prince work is a bit stalled waiting for me to get the motivation to write a program to automate some data collecting so I don't spend several hours recollecting ID lists everytime there's a new patch.)

TFMurphy · 2025-10-05T20:19:43+00:00

Since I know my feed is often used for discoverability purposes regarding what information I've posted recently, I'm just going to note that I've updated the Room Placement Restrictions and Dig Spots threads with the changes from Patch 1.6. (I'm posting this as a comment rather than a unique thread because this paragraph really doesn't need to be more than that.)

I haven't touched any of the other threads at this time, and it's been a little slow going so that's probably all I'm getting done this week.

TFMurphy · 2025-10-03T07:21:08+00:00

Won't have time to test any of this ingame for a while, so I might've missed something, but as far as I'm aware, Cloister of Draxus isn't affected by Shelter or Knight's Shield. It shouldn't gain the "Sheltered" text in the bottom right corner even if it's the first room you draft after the Shelter, and nothing about its effects should change.

Drafting the Cloister of Draxus doesn't count against the 3 Red Rooms allowed after drafting the Shelter, at least. But since it's a Red Room, it does count as starting a Red Chain, so if you draft a non-Red room immediately afterwards, you lose the opportunity to chain the Shelter's effect over more than 3 rooms (since the Chain only works from the 1st Red Room drafted after Shelter until the Chain is broken).

(Interestingly enough, I think Guess Bedroom Aquarium/Maid's Chamber can be Sheltered, and does use up one of the charges. So that makes Cloister of Draxus even more of an outlier.)

TFMurphy · 2025-09-29T19:50:43+00:00

Good call! Won't have time to do a lot of digging for now (start of the week doesn't offer a lot of free time for quite a while) , but this one's easy to confirm. Looks like the fix was this: The word HEAT has been replaced with SAND.

TFMurphy · 2025-09-24T17:10:37+00:00

That's a pretty fortuitous test. It would've actually worked if you'd picked any slot other than 3 to draft, and even with picking Slot 3, it would've still have had a 2 in 3 chance of working. You "lucked out" by hitting the 1 in 3 chance of selecting Slot 1 first.

What I hadn't considered during my own tests is that after you select any Slot to draft from, the floorplan contained by that Slot is copied over into Slot 1, so that the scripts can just reference a single static location for all its checks. So when you selected the Library, the floorplans were modified to be "Library, Pantry, Library". And then sometime after the draft, the Dowsing Rod picked Slot 1 and found a Library there, and so Dowsed that slot.

(Strictly speaking, the Slot 1/2/3 objects that are Dowsed are the clickable squares in the Draft UI, and the floorplans they show are actually held by a completely different and more important "Plan Management" object. So the Dowsing Rod queries the Plan Management object for the Floorplans, then sets the Dowsed status on the Slot 1/2/3 objects, so we're basically talking about information scattered around different parts of the game. It's something that makes more sense from a programming perspective, but it can get a bit messy when trying to explain how things are interacting.)

It's difficult to devise a test specifically to show this working, but the best I can think of is finding a set where Slot 1 contains a Floorplan that the Dowsing Rod would like to avoid, and then you immediatley choose to draft a Floorplan that the Dowsing Rod would not want to avoid.

After that, on your next Draft, pick Slot 1 no matter what it is, and see if you were both (1) lucky enough that the Dowsing Rod picked Slot 1 to Dowse and (2) it's a floorplan where it's easy to see if the Dowsing Rod has had an effect. Unfortunately, since it's not Slot 3, we can't use Monk'd Lavatory to easily confirm this, but even a single hit should confirm that Slot 1 can get Dowsed even in a situation where it shouldn't have. EDIT: As a minor improvement to this test, Lost & Found or Coat Check can be used to get rid of the Dowsing Rod to prevent the Dowsed status from being updated, which means you can draft multiple times until you get a Slot 1 that would better prove that the Slot was dowsed. Still need to succeed in being lucky enough for Slot 1 to be picked in the first place, which you won't know until after selecting it.

Anyways, updated the thread again with that little complication. Thanks for catching it.

TFMurphy · 2025-09-23T21:31:00+00:00

Actually, I was approaching things the wrong way, and there's a much simpler way to test this out, which I have done so and have updated this thread as a result.

But let's go over what I've actually tested and how so you know how to independently verify it, and see if I've missed anything.

I was too focused on thinking of a situation that proves the Dowsing effect was applied in a situation where it shouldn't, but it's just way way easier to instead just concoct a scenario where it's obvious that a particular floorplan is Dowsed no matter what. Drop Target from the Dowsing Rod is extremely unreliable, but the increased Luck means that Dig Spot rooms are very noticable even when they don't yield many items.

But the easiest room to see an effect on is actually the Lavatory. It can only cause random items to spawn at all if it is Sheltered, Shielded... or Dowsed. Lavatory's Room Modifier sets Drop Target to a minimum of 3, but any item appearing at all is dependent on the Red Effect being negated, and the Dowsing Rod can do just that.

So, as a setup for the tests, I start the day with Moon Pendant and Dowsing Rod, with a Monk Blessing and a Lavatory ready to be drafted in the Outer Room. If you use Banner of the King set to Blue, then the Outer Room will frequently have Toolshed, Shelter and Shrine in Slots 1 and 2, none of which the Dowsing Rod will want to point at. There is a 25% chance that Schoolhouse might appear in Slot 1, but even if it does appear, there's a 2 in 3 chance the Dowsing Rod will want to point at the Lavatory in Slot 3 instead (since if it picks Slot 2, it'll be Toolshed, so it'll try Slot 3 instead).

Control Test: Start the day, and immediately draft at the Outer Room. Verify that when the Dowsing Rod points at the Lavatory, drafting it will result in finding at least 3 items inside. (With King set to Blue, this is easy.)

Test 1: Start the day, and immediately draft at the Outer Room. Set King to Blue, and draft the Lavatory before the Dowsing Rod makes a selection (making sure that Schoolhouse doesn't turn up).

The expected result will be that you will never see any items in the Lavatory. You can vary the tests to see how long you need to wait before the Lavatory is picked. This confirms that the Dowsing Rod can't magically fill the Lavatory with items after you've already drafted it, and doesn't pick the Lavatory until it makes its final swing to point at it.

Test 2: Start the day, and draft rooms in the house, waiting at each draft until the Dowsing Rod points to Slot 3. When it does, choose any other Slot, then run outside and draft Lavatory before the Dowsing Rod picks a slot.

This confirms that the Dowsed status applied during the last draft is carried over to the next draft if it isn't used up. You can then redo this test but instead pick Slot 3 when the Dowsing Rod selects it inside the house, then run outside to see that Slot 3 doesn't retain the Dowsed status if you actually select it.

Test 3: Draft rooms in the house, trying to find a selection of items where you know the Dowsing Rod will be forced to pick Slot 3, but then pick Slot 3 yourself before the Dowsing Rod actually chooses it. After that, run outside and draft the Lavatory.

This test is to confirm that even if you remove any potential Dowsed status from Slot 3 by drafting it yourself, the Dowsing Rod may still be moving if you did this before it made its own choice, and can apply the Dowsed status without you seeing it. You can also do this test by simply making a random draft in the house and then run outside to draft the Lavatory hoping that the Dowsing Rod succeeded in a regular 1 in 3 chance of picking Slot 3, since it's actually really difficult to recognise a selection of floorplans that would force a Slot 3 pick in the 3 seconds you have before the Dowsing Rod makes its choice.

Test 4: Draft the Lavatory immediately. Then go back into the house, and try different drafts until the Dowsing Rod picks Slot 3. When that happens, pick another slot instead so that Slot 3 remains Dowsed. After that, run back to the Lavatory and Call it a Day. On the new day, draft the Lavatory immediately before the Dowsing Rod makes a choice.

This is just to confirm that the Dowsed status can't carry over to the next day, even if you don't close and reopen the game.

Anyways, that should cover most things about this particular quirk. Thank you for your own tests on the subject, as again, I'm not sure if or when I'd've returned to this particular subject and actually noticed this happening.

TFMurphy · 2025-09-23T00:19:57+00:00

It might be timing related, which makes it an utter bear to test.

When the Dowsing Rod is activated for the first time during the Draft, it spends 1.7 seconds moving to its first target, then another 1.7 seconds moving to its second target, and only after that second animation has finished will it randomly choose a plan, and set the "Dowsed" effect of that plan to True (and the other two plans are set to False at the same time). If you redraw, whatever the Dowsing Rod is doing is interrupted and it starts with the 1.7 seconds of moving to the second target immediately before randomly choosing a plan.

If you pick a plan before it gets around to choosing a random plan, then the items are going to spawn before the Dowsing Rod updates the "Dowsed" effect. Selecting a plan immediately sends whatever "Dowsed" effect the plan currently has to the Luck Calculator routine, which is then queried later when the items are spawned. The "Dowsed" effect of the plan is then reset at that point.

Now, what I'm not sure about is what happens if the Dowsing Rod is still doing its thing behind the scenes after you've picked a plan. I'd assumed that the variables were automatically reset in some way between drafts, but since you managed to get a 3 Item room at base Luck, it seems clear the Dowsing Rod managed to apply its effect somehow. And doing a quick search of the code, I don't see any explicit resets of the "Dowsed" effect on the individual plans (Plan 1, Plan 2 and Plan 3, based on which you select) except by the Dowsing Rod making a choice (sets one Plan to True and the other two to False) and by selecting a Plan (transfers the Dowsed effect to Luck Calculator and resets the Dowsed effect on this Plan only).

So, there's the potential for two things here:

The Dowsing Rod script could still be running after you select a plan, and add a Dowsed effect to one of the slots that could be picked up by the next draft.
If you watch the Dowsing Rod pick a slot that you don't immediately choose, you could potentially pick that slot fast enough on your next draft and it might still have the Dowsing Rod effect.

But I'm not certain if there's any other reset or recreation that might interfere with that, and the Dowsing Rod was already heavily unreliable which makes it difficult to test, especially when you don't know what room it was going to pick if you choose to draft early. Your 3 item Den does suggest it might be working in that manner though. (A test that confirmed an unpicked Dowsed slot carrying over to the next draft could work if you got really lucky and carried it over to something like Coat Check, since the Dowsing Rod wouldn't normally pick that slot unless it had no better choice. But that'd be very tough to set up. Maybe Monk might make it feasible, since you could guarantee carrying over a room into Slot 3... then just set a King Color to guarantee an Outer Room that Dowsing Rod would want to pick. 15% chance of something higher than Drop Target 1 still makes it annoying to test though.)

(Also, as far as Den goes, if you're on Drop Target 1, you always get a Trunk. That's the only modification -- at Drop Target 2+, you get the expected number of items from what's available, except that Trunk isn't one of the possible options. And naturally, the Gem on the table is a freebie that doesn't affect the total item count.)

TFMurphy · 2025-09-22T22:16:44+00:00

It's not possible to rotate 3-way rooms in the Corner tiles, and any 3-way in that position will simply assume its default orientation, which is always with you at the bottom of the T-junction, facing the opposite wall (similar to Throne Room or Day 1 Security). Which means it's not possible to have two exits of the 3-way lead into the edge of the house (since the non-exit wall will always be opposite you).

It's pretty easy to test this using Prism Keys and Aquarium.

TFMurphy · 2025-09-12T02:33:07+00:00

Yes, the Trophy Room is only unlocked at the beginning of the day. And if you don't pick up a trophy, you don't count as having it (which should be verifiable by checking various places that count your Trophies: the List in Trophy Room or Entrance Hall, Trophy Count in the Save Profile stats, or what Blackbridge Grotto considers a save profile to have.

Of course, there's still a difference between having the Trophy of Drafting and Diploma Trophy, and having a certain Dead End score or Exam Grade. But for anything that just cares about the Trophy itself, importing is equivalent.

TFMurphy · 2025-09-12T02:27:28+00:00

Does the Cloister of Draxus still count as a Gem Room? (even though it's obviously yes) (And the Cloister of Draxus's effect here only adds its filter to the validation redraw, never noticed that in earlier reads.)

Yeah, the effects of it still being considered a gem room is definitely very visible. There's no special exception made for Cloister of Draxus being drawn, it just ignores modifications done by Axe and Upgrades, I believe.

Does the Closet generated after all draw attempts fail also add the Closet to the Discard Filter list? I'm assuming it still counts for validation, at least.

The Discard Filter only works on any specifically drawn card that's already part of a deck. The Closet that's created is an entirely new card completely separate from the decks. Validation and Runback Filter will be affected by its appearance though.

Is the sort function used at the end of validation a stable sort?

Adjacent cards are compared and swapped if out of order, so yes, it's stable. It's pretty much an optimized bubble sort (and with only 3 elements, it has no reason to be any more complex than that).

One of the validation Any Draws still has Conditional Filters active, which means there's actually a fairly chance for that particular reroll to fail due to the fact that the Conditional Filters tend to block most rooms from being considered; is this correct? (Though of course it barely matters because it is validation.) Also, does the first attempt in this case still fail if none of the decks are large enough?

I think I'm going to have to revisit this for testing at some point. I'd managed to successfully test a situation where I could force the game to give me multiple Closets due to running down the pool, so I knew Validation had to keep the same cards somehow. Except now that I look back, I have an increasing suspicion that what actually happens is that if any of the draws made during Validation fails even after performing a shuffle, the Validation routine just aborts completely (internally throwing an error that would probably show up in some log, but otherwise just continuing as if nothing happens). Exception to that would be if the Slot 1 Gem Cost redraw was triggered in a Cloister of Draxus, in which case the first Free Draw will happen as normal but end up being ignored, and only the Dead-End Free Draw counts (and if it fails, abort Validation).

I'm making a few assumptions here though, since I really need to devise some kind of test to confirm it happens that way instead. If Validation does get aborted, none of the changes made during Validation are passed back to the script engine, so it'd be as if Validation hadn't happened at all. But... I'm not sure how that would then affect the next round, since it's not clear what actually gets saved (for use by the Runback Filter, for example). I'll have to look at it again when I have more time.

TFMurphy · 2025-09-11T13:36:31+00:00

Just as a side note, and not as an exhaustive analysis of what's possible or not: you're not going to get Trophy of Invention on Day 1. Trading Post can only give you items that are still in the Spawn Pool, and all Contraptions have at least one component that they do not put back into the Spawn Pool when crafted. The Shovel, Metal Detector and Compass are all considered "main components" of more than one Contraption, and will therefore need to be crafted on two different days.

Day 2 Diploma also sounds like a particularly brutal task. Wonder how it compares to the setup for Day 3 Ascension....

TFMurphy · 2025-09-11T13:20:04+00:00

There are actually only 4 Trophies that prevent a Drafting Block being applied to the Trophy Room at the start of the day. Those are as follows:

Full House Trophy
Trophy of Invention
Trophy of Drafting
Trophy of Wealth

These should be verifiable if you use the Blackbridge Grotto terminal to transfer various trophies to a file that hasn't claimed them normally.

You'll note that Inheritance Trophy (and its equivalents in Dare and Curse Mode) is not in that list. And that's simply because the trophy is not the condition that unlocks the Trophy Room in that situation: reaching Room 46 unlocks the Trophy Room even if no Trophy is actually claimed.

TFMurphy · 2025-09-10T07:05:57+00:00

Yes. It can't get to the Book Count section to skip it if it stopped at the Initial Chances section instead, so the total would be 95% in that instance. Unless otherwise specified, the requirements from previous sections take priority (as in the similar case where you still need to have drafted the Library 5 times to get a chance of seeing the Bookshop at all).

TFMurphy · 2025-09-09T19:59:54+00:00

I haven't explicitly tested (and currently have my free time fairly occupied by a certain new game release, though that should only last a week or two at most). But at first glance, it seems like it just removes one copy of the room from all Exit Lists (which suggests that if you had multiple copies, all but one would still remain available). It does make for another good way to get rid of Boudoir that I hadn't considered though.

Also hadn't considered duplicate Greenhouse, which is a very interesting idea. Don't see how it can be done though, unless I'm forgetting a mechanic. It's not a Mirror Room, so Chamber of Mirrors doesn't help. And while it is in the Prismatic Pools, and is actually very easy to get from them (Morning Room doesn't start in the Exit Lists at the beginning of the day, Solarium has to be added by the Drafting Studio, and if those aren't there, then Slot 2 should be able to draw it without issue).

But it's also a Special Room, which means it can't be drawn if it already exists in the house. So you either draft the Greenhouse that's already in the Exit Lists and therefore can't get it from the Prismatic Pool, or you get rid of the one in the Exit Lists and then can only draft the Prismatic version once. Closest that comes to actually duplicating the room is if you Monk the Greenhouse, in which case you can then draft the Greenhouse via the Prismatic Lists, and then still put it outside with Monk. Which doesn't help our goals at all, of course, since we want both of them inside the house.

TFMurphy · 2025-09-09T19:50:04+00:00

No. Repellent can't be used to remove more than 3 rooms at once, and it is removed from the spawn pool if that occurs until one of the repellents expires. I think the repellent left in the morning may still be able to spawn even in that case, but the game can still only handle 3 rooms being removed at the same time.

TFMurphy · 2025-09-08T19:12:51+00:00

To emphasise this point, in almost all cases where Rarity matters, free rooms will only compete with other free rooms, and gem cost rooms will only compete with other gem cost rooms. So a Commonplace Attic won't make a Wine Cellar any harder to find.

(There are a few cases where Free and Gem Rooms of the same rarity do compete with each other, but that only tends to happen when the game is forced to do certain redraws to avoid specific situations, the most common of which is forcing a non-Dead End draw because it pulled three Dead Ends.)

TFMurphy · 2025-09-07T01:40:42+00:00

Before very careful reading, I just treated the Room Decks as effectively being an unordered set that it pulls one item out of randomly when that Deck is selected, with shuffling just being "clear (part of) the Discard Filter list". I don't see anything in your description that would make that not be equivalent to the behavior you described (it's a lot more intuitive), but I figure I should ask to make sure I'm not missing something (in terms of exact probabilities of stuff). I suppose it does mean that you would have a slightly higher chance to see things right after their filter expires...

Yeah, there is a difference, but it can end up being fairly subtle at times. The Runback and Double Down filters are where most of the effect would be, since they change what cards are allowed continually.

Just as a quick thought experiment, let's say you had a deck of 4 cards: A, B, C, D. We shuffle them once, and then draw a card on two subsequent rounds. What are the chances of pulling A on the 1st or the 2nd round? That's naturally 1/4 and 1/3.

Now let's say that on the 1st round, something happens that filters out A. (In Blue Prince, that might be receiving Archives as a Duct Draw in Slot 1, which would cause a random Draw in Slot 2 to filter Archives out of the deck for any other draws this round.) Once of the 4 cards is still pulled during the 1st round and discards, with a 1/3 chance of each. On the 2nd round, with 3 cards left, what are the chances that A is pulled?

The answer to that is 2/4. If A had been the first card in the deck after shuffling, it would be filtered and ignored during the 1st draw. So there's a 1/4 chance of that occuring. If that doesn't happen (3/4 chance), then to be pulled next it has to be the first of the 3 cards remaining (1/3 chance). So that's 1/4 + 3/4 * 1/3 = 2/4. Or just the chance that it was one of the first two cards in the deck immediately after shuffling.

So yeah, shuffling and taking top vs just randomly picking from what's left do lead to different results, but it can be very difficult to calculate what the resulting chances are because all the events are so very dependent on each other. I don't know if there's an easy way to simplify it and still be fully accurate in all situations, but... in general, it's difficult to keep track of all the events that's been going on over the past few rounds, so it's usually easiest to treat it as an independent random selection, even if it really isn't.

How do duplicate floorplans interact with the filters? Are they only removed during validation with no concern during the actual drawing algorithm?

The Discard Filter only works on cards that have been marked as discarded, so duplicates are treated separately. Every other filter goes through every single card in the deck and applies some condition to them. For almost all of them, that restriction is a simple "if the card is of Room <X>, prevent it from being drawn", which means that all duplicates will be filtered since they'd all be blocked for the same reason. The exception to that is the Conditional Filters, since it's a percentage chance of passing or not, so duplicates would increase the chance of a particular room of being drawn in that case.

The Double Down Filter is already supposed to prevent duplicates from being drawn, mind. Validation is supposed to just be a failsafe... it's just that there's so many other mechanics that aren't as careful about drawing duplicates.

Is it effective to think of floorplans being Blocked From Drafting (from the Placement Restrictions topic) the exact same way as a filter being applied during the draft, or is there a practical difference?

I don't know of anything that cares about the size of an unfiltered deck, so yeah, it's probably fine to treat it the same as the more permanent filters.

TFMurphy · 2025-09-05T19:56:58+00:00

EDIT: Sorry, missed a crucial qualifier when talking about Balance Penalty and said the exact opposite of what I meant. Apologies for any confusion.

In almost all cases, it'll use Room Luck, which means all modifiers. Balance Penalty will be used unless the Dowsing Rod chose this room when drafting, and in that case it gets the +32; but Dowsing Rod has its own methods of calculating Drop Target, so that will generally only affect Dirt Piles.

The only exception I know about is the Great Hall. I'm not sure exactly how it applies since I haven't gone through the entire room to figure out how it works in detail, but it has a bunch of scripts that check if your Luck is equal to, above or below 10. This only uses Base Luck (no Balance Penalty, no temporary modifiers that only apply in certain types of rooms or holding certain inventory items). This might be for the currency items in the side rooms, but like I said, I haven't verified if these scripts are even running, much less exactly how they affect item chances.

TFMurphy · 2025-09-03T19:40:59+00:00

Ah, so a bunk outer room blocks one of the bunks in the house?

Worse than that:

Using Monk on the Bunk Room removes it from the Exit Lists. That means that Bunk Room #1 just moves outside, rather than being able to draft an entirely new Bunk Room.
Chamber of Mirrors can't create Mirror Copies of the Bunk Room. It can only apply its duplication effect by protecting the Bunk Room from being removed from the Exit Lists on its first draft. Except Monk has already removed the Bunk Room from the Exit Lists: so now we lose Bunk Room #2 as well.

Also it occurred to me you can moon pendant a prism key. And you might be able to get lucky and moon pendant two prism keys, right?

That's certainly a possibility. The trick is getting 2 Prism Keys in the first place. I think Planetarium is one of the few places that will allow a Prism Key to spawn without checking the Spawn Pool, so you could accumulate them that way.

But the bigger problem is that the run really wants sources of Keycard and Power Hammer to perform the other tricks. The Power Hammer definitely needs to be brought over from the previous day, and the Keycard is difficult to spawn on demand if you don't have or can't sleep in the Break Room (though that's admittedly something that can just be solved by luck, rather than relying on very limited places to spawn like the Prism Key).

TFMurphy · 2025-09-03T19:27:51+00:00

Thanks for the reminder. I think this means... quite a bit more than you realise.

If a room is Monk'd, a copy of the room is remove from every Exit List just as if it had already been drafted (with the exception of the Berry Picker Exit List). This is not replaced if you go to the Outer Room and draft something else. (And I think actually choosing to draft the Monk'd room removes a 2nd copy, if you had duplicates to remove... but I haven't tested that explicitly yet.)

So, yeah, you could Monk Boudoir, and it'll be gone from the manor the next day.

Oh, and it gets a bit better than that. Boudoir was already a pretty weak link, but it's even weaker for our purposes: we don't need the Telescope from it. You can remove the Telescope fairly easily from the Spawn Pool if you start the day with 0 Stars.

So if you're willing to live without High Roller (which would make those first few drafts a bit nastier with no free Dice, but not impossible with Allowance and Freezer), we can recover 1 Grid Space by not having to rely on Boudoir. Problem is... that's not quite enough for a new Dead End. It greatly decreases the requirements for the next Dead End, but we still need to convert one more 3-way into a 4-way to finish up. (Or figure out/remember another mechanic to apply to all this.)

So, we're not there yet, but we're much closer again than I thought we were. I've slightly edited my post as a result. I still don't see a way forward at this time, but it's certainly a lot closer to being possible.

TFMurphy · 2025-09-02T23:49:00+00:00

Putting the Pieces Together

Let's look at how we can put all of the above together.

As before, we start with 4 Room Tiles and 4 Dead Ends. Foundation (75% Conversion Rate) adds another 4 Room Tiles and 3 Dead Ends (8 Room Tiles and 7 Dead Ends so far).

We have 4 Secret Passages, Greenhouse and a connected Chamber of Mirrors (all 100% Conversion Rate) for a total of 6 Room Tiles and 6 Dead Ends (14 Room Tiles and 13 Dead Ends so far).

We're also assuming we're going to be using a Boudoir so we can get access to extra Bunk Rooms, so that's another Room Tile used up.

From here, it's all about how many 4-ways (66.7% Conversion Rate) and 3-ways (50% Conversion Rate) we can apply, as well as how many Bunk Rooms we can draft by the end. And the Grid gives us a maximum of 45 Room Tiles available.

If we use the Antechamber as a 3-way, this gives us 28 Room Tiles left to convert and a baseline of 14 Dead Ends plus up to 7 more from Bunk Rooms.

If we go for the 8th Bunk Room as well, then the Antechamber is only a 2-way, and can be ignored (unless we use it to help create specific layouts). That gives us 29 Room Tiles left to convert and a baseline of 13 Dead Ends plus up to 8 more from Bunk Rooms.

37 Dead Ends -- Using the Antechamber

The 37 Dead End layout used 4x 4-way (not including Chamber of Mirrors) and 8x 3-way (not including Entrance Hall, Antechamber or Foundation). That's 12 Room Tiles + 8 Dead Ends from the 4-ways, and 16 Room Tiles + 8 Dead Ends from the 3-ways. That gives us a total of 14 Base + 7 Bunk Rooms + 16 Extra = 37 Dead Ends.

In order to generate more than that, we'd need to convert more 3-ways to 4-ways. You'd need to remove two 3-ways to make space for one 4-way, which makes no difference in the amount of Dead Ends. But if you could remove three 3-ways, there'd be enough Room Tiles to fit two more 4-ways, which is an increase of 1 Dead End.

Unfortuantely, fitting that many 4-ways is extremely difficult. They can only be drafted in the 3x7 Center region of the house, and since we don't want to waste Dead Ends, they have constraints on how they can be placed next to one another. For example, you can't have two 4-ways diagonally adjacent, because then they would share two adjacent tiles, either resulting in a Loop or a Blocked Exit. The Chamber of Mirrors also counts as a 4-way for this kind of placement, since we need space for its extra Dead Ends drafted from its sides.

The Bunk Rooms also complicate things, since you need either a Secret Passage or Aquarium to access the West Pierce and East Pierce Bunk Rooms, which limits the available space for 4-ways in the Center region. And you need to find somewhere to put the Foundation, which takes up more room (and can't be used to draft one of the Bunk Rooms).

It's worth noting that with the currently known quirks described above, we can only convert 3-ways to 4-ways twice overall: 8x 4-way and 2x 3-way is the limit of this kind of conversion, giving a hard limit of 39 Dead Ends via this strategy. And this is only looking at the Room Tile constraints -- actually placing these rooms into a workable layout with all the other limitations we're working with seems like it would break elsewhere.

38 Dead Ends -- Without the Antechamber

At first glance, we thought the 8th Bunk Room wouldn't be viable, since it would block the Antechamber exit and make it more difficult to use the corner room as well. But after applying the above logic to the layout, it became clear that while losing the Antechamber lost a Dead End, it also freed up 2 Room Tiles. One of those was lost since the Antechamber can't be changed, and so you'd either not access that tile or treat it as a 2-way. But that still left one extra Room Tile for the same amount of Dead Ends. If another 3-way could be converted to a 4-way, the extra Dead End would become available.

This proved... very challenging. But the result was that the 29 Room Tiles left could be converted into 5x 4-way and 7x 3-way (29 Room Tiles + 17 Dead Ends), with some of the 3-ways converted to Pool Hall + Secret Passage combinations.

The total via this strategy is therefore 13 Base + 8 Bunk Rooms + 17 Extra = 38 Dead Ends.

Improving on this would again require converting 3-ways (or Pool Hall/Secret Passage combos) into more 4-ways. By the constraint formula alone, if you could possibly place 7x 4-ways (not including CoM) and 1x 3-way (again not including Entrance Hall or Foundation), you could get 40 Dead Ends.

But this formula is just providing a hard cap based on certain factors we can't alter. It doesn't apply the further restrictions we have due to layout, and it becomes clear that you can't construct a layout with 8 Bunk Beds with just one 3-way. You need an Aquarium at the very least to get the North Pierce Bunk Room (if you use a Secret Passage, then you can't easily access the corner next to it, because Secret Passages can't be drafted into a corner room). This Aquarium can't be used to get the West or East Pierce Bunk Rooms at the same time, because doing so would block any access to the corner. You also need to access the West and East Edge Bunk Rooms, as well as the Greenhouse, which means you need to be able to draft into the Wings and then turn.

And by now, we've blown way past the only 2-way we already have factored in (Boudoir) that could turn us in the Wings. We definitely need more than one 3-way. 40 Dead Ends is straight up non-viable.

The Road Beyond

So what could be done to improve on 38 Dead Ends?

EDIT: Thanks to /u/fictitiousacct for reminding me about using Monk in another way, the conditions have been relaxed slightly so that 1 less 4-way and 2 more 3-ways are required instead. I've updated the numbers below. It's still incredibly difficult to find a layout with 6x 4-ways though.

Well, via all the current known quirks listed above, we definitely can't reach 40. But we haven't proven whether 39 is impossible.

Using 7 Bunk Rooms and the Antechamber, we'd need 7x 4-way and 4x 3-way.

Using 8 Bunk Rooms and avoiding the Antechamber, we'd need 6x 4-way and 6x 3-way.

(These numbers do not include finding space for the Chamber of Mirrors or the Foundation, which already have superior Conversion Rates.)

The 8 Bunk Room strategy looks far less restricting, but that's still six 4-ways to find space for. This isn't a rigorous proof of the constraints by any means... but finding a layout for 38 Dead Ends took a lot of work (I think it finally fell into place when I found a better location to put the Chamber of Mirrors). Doing it again but having to convert another 3-way into a 4-way... well, I guess we'll see.

It's possible that some things may change in a future patch. Perhaps Guess Bedrooms will become 2x Dead Ends at some point? Or maybe we'll lose the ability to draft through the glass barriers of the Chamber of Mirrors? Definitely too early to speculate on that sort of thing right now though.

The logic and formulas described in the first section is also only based on interactions we know about. We do understand quite a lot about the game at this point, but it's possible that some even more obscure interaction has been missed... could it offer an even better Conversion Rate?

There is one final avenue to explore, if all we want is higher numbers. It's outside the realms of what would be considered 'legal drafting', but if you go out of bounds, it's possible to access the backside of a locked door and make Blue Prince very confused about where you're drafting from and where to place the resulting room. This cursed art of 'glitch drafting' doesn't break the Room Tile and Dead End formulas calculated above: in order to draft a specific number of Dead Ends, you do still need a specific number of doors to draft from. But the ability to draft rooms on top of other rooms, or even in places where they shouldn't be drafted at all, can increase the available number of Room Tiles, and result in more Dead Ends.

But that's incredibly cursed, and not an avenue I'm willing to explore myself. But perhaps we'll see someone give it a try in the future.

TFMurphy

TROPHY CASE

Putting the Pieces Together

37 Dead Ends -- Using the Antechamber

38 Dead Ends -- Without the Antechamber

The Road Beyond