Viewing Mod
The Binding of Isaac: Mystified
Reworked item rarities, pools, rooms, final bosses and more!
Created 8 years ago

THIS IS AN AFTERBIRTH ONLY MOD. FOR THE AFTERBIRTH+ VERSION, PLEASE CHECK THE STEAM WORKSHOP PAGE.



Are you tired of OP/game-breaking builds being handed to you on almost every run? Do you miss the pacing and the resource management from the original Binding of Isaac? Do you want a proper difficulty curve, where a run starts off easy and actually gets more challenging as you progress?
Then this mod might be for you!

It started as an attempt to make Afterbirth interesting again for myself, as I was slowly getting annoyed by the game's overall lack of balance (compared to both Vanilla Isaac and my recent addiction, Enter the Gungeon). Therefore, the mod is quite personalized and will probably appeal to a small audience only.

Recommended to play on normal difficulty while using the included save file.


KEY FEATURES

Item pools were completely reworked from scratch to adjust the average run power and to make them feel more unique. More items are now considered special and item rarities have been introduced (common, uncommon, rare).
Also, the amount of obtainable items, trinkets and pickups has been reduced, with a few remaining ones working differently than before. This will be a big turn-off for some people, but I decided from the very beginning to value core gameplay over the sheer amount of items (there's still a big enough variety imo). In fact, my previous mod already attempted to rebalance the game without cutting content, but I didn't like the result.

Room layouts got a major treatment as well. Most non-standard-sized rooms have been removed, but all of the remaining rooms can appear regardless of the chosen difficulty, effectively increasing the overall room variety. Further changes are made to prevent unfair damage and to encourage resource management.
100+ new rooms have been added, notably to the final floors. Special rooms have been revamped to make them all relevant but not overly powerful. Oh, and proper final bosses await you at the end of The Chest or Blue Womb. Yes, I said Blue Womb.

The soundtrack is replaced by the original Danny B soundtrack and the announcer has been removed.

Tons of other tweaks and fixes ...including graphics, items, enemies, descriptions, ambush waves, and more. Most of these are pretty subtile though, as I still want this mod to "feel like Isaac".

See the attached text file for more details.


KNOWN ISSUES

If you find a bug that is not listed below and not already present in the regular game, let me know.
  • Shops have an empty deal when there would be a battery pickup on sale
  • Hearts cannot spawn in the library/cathedral-styled top secret rooms
  • The mod might not work properly on Mac/Linux


VIDEOS

https://www.youtube.com/watch?v=AVjMYBUF6tI&t=2s
https://www.youtube.com/watch?v=74PnZjABNBg

590

downloads
x 83

- FINAL AFTERBIRTH UPDATE (moving on to AB+ for further updates)

- Guppy's Collar is now just an HP up

- moved Guppy's Collar from the Treasure pool to the Boss pool [C]

- added Guppy's Tail to the Devil pool [U][S]

- removed Dead Eye from the Devil pool

- moved Notched Axe from the Treasure pool to the Shop pool [C]

- replaced Super Pride with Ultra Pride and also removed the him from normal rooms, making Dead Cat unobtainable

- replaced Ultra Pride with Angel encounters

- removed the previous Angel encounters from Sheol/Cathedral

- changed Uriel/Gabriel HP to 60 + 45 stageHP (same as Krampus/Fallen)

- changed Bob's Rotten Head to a passive (adds 1 black heart) and gave it a costume

- changed IV Bag to a passive (Speed up + heals 3 hearts), gave it a costume

- Blood Bag doesn't give Speed up anymore, only heals 3 additional hearts and got a sprite change

- The Ankh now adds 1 soul heart on pickup

- replaced all Quarters with Store Credit (adds 15 coins)

- reverted the visual change to Slot Machines

- reverted Monster Manual's charge time

- <3 doesn't heal anymore

- tweaked a few room layouts

- might have missed some changes due to making them months ago

- fixed a small item pool mistake introduced in the previous update

- re-added Golden Remote (Undefined) [U] to the Treasure pool

- re-added champion variants for Pooters and Super Pooters

- changed some room layouts

- added A Box, Mom's Coin Purse, The Sad Onion (Pisces), The Alchemy Index (Converter) and 20/20 [R][S] to the Treasure pool

- removed Demon Baby and Little Seraphim from the Treasure pool

- added Stigmata [U] and Curved Horn [U] to the Boss pool

- removed A Box and Mom's Coin Purse from the Boss pool

- changed BFFs' rarity in the Shop pool from [U] to [C]

- added Serpent's Kiss, Abel and Dead Eye [U][S] to the Devil pool

- removed Dead Bird from the Devil pool

- changed Rotten Baby's rarity in the Devil pool from [U] to [C] and made it a non-special item

- added The Alchemy Index (Converter) to the Library pool

- removed Whip Worm from the Trinket pool

- changed A Sack of Pennies' effect

- reskinned a couple items

- added skin colour alts for Serpent's Kiss

- made Mimics invincible

- made TNT barrels easier to push

- tweaked a few special rooms

- reverted Stone Chests back to normal as they could otherwise cause a glitch with the Key Master

- added 20+ new rooms

- moved the Chest/Blue Womb trap rooms to Cathedral/Sheol

- reworked several special & normal rooms

- reduced boss rush waves to 10

- added 2 new enemy variants

- enabled Pin's champion version

- changed both Uriel's and Gabriel's HP to 600 (including their fallen variants)

- reverted big and medium Fistula's contact damage to full heart

- changed small Teratoma's contact damage to half heart

- added a short cooldown to Razor Blade (30 frames) and Magic Fingers (15 frames)

- changed <3 to heal 3 full hearts instead of 99

- reverted The Satanic Bible removing a heart container + adding a soul heart on pickup

- reverted Sacrificial Dagger removing a heart container + adding a soul heart on pickup

- reverted Goat Head removing a heart container + adding a soul heart on pickup

- changed Goat Head to a special item

- changed Ceremonial Robes (Black Candle) to not add a black heart on pickup

- added Ceremonial Robes (Black Candle) to the Shop pool

- removed Restock from the Shop pool

- changed The Ankh's rarity in the Shop pool from [U] to [R]

- added Dark Deal (Missing Page 2) and Headless Baby to the Devil pool

- removed Abel and Ceremonial Robes (Black Candle) from the Devil pool

- added Dark Deal (Missing Page 2) [U] to the Curse pool

- removed Sacrificial Dagger from the Curse pool

- removed Guardian Angel and Portable Slot from the Treasure pool

- changed The Inner Eye's rarity in the Treasure pool from [U] to [C]

- added Rosary Bead and Purple Heart to the Trinket pool

- removed Rusted Key from the Trinket pool

- replaced A Quarter with Store Credit (+15 coins)

- replaced A Dollar with A Quarter

- tweaked the slot machine sprite

- tweaked the Razor Blade sprite and Blood of the Martyr's costume

- added a costume for Heart Locket

- changed devilprice to 1 for all items (only relevant for Black Markets when the player has Chaos)

- Lokii, Dangle, Turdlings, Steven, C.H.A.D., Gish and Triachnid now act as rare alts instead of unique bosses

- moved Gurdy Jr. down to Stage 1 + decreased her HP from 250 to 200

- moved Polycephalus back up to Stage 2

- moved Lokii down to Stage 3 + decreased his HP from 350 to 250 (= 500 total)

- moved The Carrion Queen up to Stage 3

- moved The Gate up to Stage 3/4

- The Bloat cannot appear in Stage 3 anymore

- switched around some other "boss rarities"

- increased Mega Clotty's HP from 20 to 62

- removed some previously added champion variants

- added Little Seraphim, Little Gish and Little C.H.A.D. to the Treasure pool

- removed Mom's Coin Purse from the Treasure pool

- added Moldy Bread and Mom's Coin Purse to the Boss pool

- removed Stigmata and Curved Horn from the Boss pool

- decreased the rarity of Caffeine Pill and Squeezy in the Boss pool from [U] to [C]

- decreased the rarity of Sacrificial Dagger in the Devil pool from [U] to [C]

- increased the rarity of Contract from Below in the Devil pool from [C] to [U]

- added Moldy Bread to the Beggar pool

- removed Jesus Juice from the Beggar pool

- removed 4 pills: Percs, Addicted, ??? and Full Health (the latter can still be triggered via Bad Trip pill)

- Sacrificial Dagger now removes a heart container and replaces it with a soul heart

- fixed a bug with the Magician card caused by the new Spoon Bender costume

- added a costume for The Left Hand

- Contract from Below now uses the Addicted costume

- reskinned Spike Chests

- fixed some libraries that never spawned

- fixed the "special encounter" rooms in Sheol

- added new Sacrifice Rooms

- tweaked a bunch of other rooms

- decreased The Ludovico Technique's rarity in the Treasure pool from [R] to [U]

- changed The Ludovico Technique to a non-special item

- updated the included save file: now also locks Sticky Nickels and all Special Shopkeepers, as well as Keeper for the sake of random runs

- added a chance for Greed/Super Greed miniboss rooms getting replaced by a small shop (indicated by a hanging shopkeeper)

- increased the difficulty of some rather trivial trap rooms

- reduced the number of waves in Boss Rush from 15 to 13

- reduced the number of Afterbirth's "replacement enemies" in rooms, e.g. Burning Gapers

- reduced the number of fireplaces in Basement/Cellar and some special rooms

- added a reward for special encounters in Sheol/Cathedral

- Portable Slot can now appear in Arcades

- The Ladder can now appear in Libraries

- PJs can now appear in Bedrooms

- tweaked a couple other rooms

- added Chaos [U], Infestation 2 [U][S] and Mom's Coin Purse to the Treasure pool

- removed Dead Eye, Explosivo and Tear Detonator from the Treasure pool

- added Restock [R], Heart Locket and More Options [U] to the Shop pool

- removed Chaos from the Shop pool

- decreased The Jar's rarity in the Shop pool from [U] to [C]

- added Sacrificial Dagger [U] to the Devil pool

- removed Lil Brimstone from the Devil pool

- added Goat Head [R] and Sacrificial Dagger [U] to the Curse pool

- decreased Ceremonial Robes' rarity in the Curse pool from [U] to [C]

- added Prayer Card [R] to the Library pool

- added A Sack of Pennies to the gChest pool

- added Mom's Coin Purse to the rChest pool

- decreased Latch Key's rarity in the Boss pool from [U] to [C]

- Goat Head now removes 1 heart container and replaces it with a soul heart

- The Satanic Bible now removes 1 heart container and replaces it with a soul heart on first pickup

- Mom's Coin Purse now adds 5 coins

- reduced Sacrificial Dagger's hitbox from 13 to 8 (same change as other non-Pretty Fly orbitals)

- PJs doesn't heal + only adds 2 soul hearts

- removed Lazarus' starting pill

- reverted changes to Samson's starting items

- overhauled title and menu screens

- reskinned Aquarius as Depression

- changed several costumes and added skin colour alts (e.g. Spoon Bender)

- updated a few item decriptions

- added a 20% chance of Krampus getting replaced by a regular Devil Room (indicated by purple fireplaces)

- reworked Black Markets and Secret Rooms

- tweaked a few other special rooms

- removed A Deck of Cards and Mom's Bottle of Pills from the Shop pool

- decreased Options' rarity in the Shop pool from [U] to [C]

- removed Golden Remote (Undefined) from the Treasure pool

- added Proptosis [U][S] to the Treasure pool

- added skin colour alts for Proptosis, Lump of Coal, Wooden Spoon, Stigmata, Cat-o-Nine-Tails and E. Coli

- changed The Mulligan to a non-special item

- changed the colours of Cricket's Body to match Cricket's Head

- fixed the "hole in wall" animation in the Blue Womb

- removed champion variants for Blue Boils, Greed Gapers, Mom's Hands and Mom's Dead Hands

- reverted the latest changes to the card pool

- fixed the Demon Beggar "double donation" exploit

- improved the new Contract from Below costume

- fixed reflections on The Jar of Life

- fixed the stupid wall texture in The Chest

- recoloured props in the "???" floor

- added skin colour change for Mysterious Liquid

- tweaked the Science costume (again)

- tweaked the Contract from Below costume

- removed the flashing effect from The Polaroid's and The Negative's aura

- lowered costume priority for The Polaroid and The Negative

- fixed Contract from Below not using its skin alts

- reskinned The Book of Secrets as The World Atlas

- removed The World Atlas from the Secret pool

- added The World Atlas to the Shop pool

- removed The Monster Manual from the Shop pool

- added The Monster Manual to the Treasure pool

- removed Pandora's Box from the Treasure pool

- added Pandora's Box to the Secret pool

- updated the Mystified icon

- every item that appears in a regular item pool now has a VERY LOW chance to appear in all other item pools

- ...this prevents early "breakfasting" with Chaos and occasionally creates an unexpected item drop

- added A Deck of Cards, Mom's Bottle of Pills, Charged Baby and Chaos [R] to the Shop pool

- changed Broken Stopwatch's rarity from [R] to [U]

- changed The Jar's rarity from [C] to [U]

- changed The Candle's rarity from [U] to [C]

- added Tear Detonator and Friend Zone (Best Bud) to the Treasure pool

- removed Ventricle Razor and Little Gurdy from the Treasure pool

- changed Bumbo's rarity from [C] to [U]

- added The Book of Secrets to both the Secret pool and the Library pool

- added The Habit to the Curse pool

- added A Box, Jesus Juice and Odd Mushroom (Large) to the Beggar pool

- added The Jar of Flies and Friend Zone (Best Bud) to the dBeggar pool

- added The Sad Onion, The Boomerang and Boom! to the gChest pool

- removed Wire Coat Hanger from the gChest pool

- added PHD to the rChest pool

- changed the bBeggar pool to contain all items from regular item pools

- added 7 trinkets and 3 cards back to the game

- added 10 new rooms to Womb/Utero

- added 10 new rooms to Depths/Necropolis

- added new Secret Rooms, Top Secret Rooms, Curse Rooms, Sacrifice Rooms, Arcades, Shops and Treasure Rooms

- tweaked several special rooms and a couple normal rooms

- revamped Crawl Spaces/Black Markets

- changed some remaining random pickups in rooms to more specific ones

- made stone chests impossible to push around

- increased Flesh Death's Head collisionMass

- improved Chaos' item sprite

- matched Chaos' blue skin colour alt to previous changes

- tweaked the costume for Lord of the Pit

- added a costume for Explosivo and Doctor's Remote

- tweaked the costume for the Mom transformation

- added skin colour alts for the Conjoined, Spun and Mom transformations

- fixed Mysterious Liquid ignoring skin colours

- increased priority for some costumes to prevent wrong body/head colour combinations

- adjusted the Blue Conjoined Fatty's spritesheet to match the Blue Gaper's colour

- moved the Key Block sprites up by 2 pixels

- reverted the addition of champion variants for Hangers (caused a bug with their rope)

- reverted changes to the Whore of Babylon "giantbook" animation

- changed a small detail in the "Top Secret Shop"

- adjusted blue character spritesheets to match previous changes

- removed 2 golden chests from the final floors' starting rooms

- added It Lives as a rare Mom's Heart alt

- added Blue Baby as a rare Isaac alt

- reverted changes to Blue Baby's HP

- removed the "special encounter" rooms in The Chest & Blue Womb

- changed the Isaac fight music to the correct one from Vanilla

- added Scapegoat and Dark Matter [U] to the Treasure pool

- decreased Evil Eye's rarity from [U] to [C]

- fixed costume overlapping for Dark Matter & Contract from Below

- added skin colour alts for Dark Matter & Contract from Below

- matched Science's costume to the default blue skin colour

- reverted previous changes to the Science costume

- fixed a visual glitch involving Fate & Lord of the Pit

- added the Razor Blade costume to the "new" Razor Blade

- reverted priority changes to Razor Blade & Whore of Babylon

- reverted some changes to the Top Secret Rooms

I Wonder If It'd Work With Godmode- OH MY GOSH THAT'D BE AWESOME
or already Mowlem that this mod is awesome
I'm loving this mod. It's almost a carbon copy of another mod that I was working on with 5136 in private. We changed the balance, made Hush and Ultra Greed final bosses, etc.

I do, however, have a suggestion. This is a feature that was in the private mod. Instead of having players choose Polaroid or Negative, make them "rare drops" (make two mom rooms with a relatively low weight and place polaroid in one, negative in another). That way, only one of the two will spawn, and only occasionally, putting an incentive on taking that path.

Another suggestion would be to make The Lamb and ??? bosses for Cathedral and Sheol alongside Isaac and Satan, so there's a chance to get either. This was also in the private mod.

What do you think of the suggestions?
Glad you're enjoying the mod.

I really like your first suggestion. In fact, I originally wanted to do something similar to make streaks more interesting but assumed it wasn't possible due to the Mom boss room always dropping Polaroid + Negative (once unlocked). I'll do some testing and maybe add it in the next update.

As for your second suggestion, I'm pretty happy with the current Lamb fight tbh. Also, I'm pretty sure that if you move him to Sheol, you'll only hear ambient noises instead of the boss music.
??? is still part of this mod, he's just a "special encounter" for now. I might turn him into a rare Isaac alt like you said though (I mean, he IS an Isaac alt afterall).
The way that we managed to achieve Polaroid/Negative was twofold.

First, we locked Polaroid and Negative behind an unused achievement along with the default one.

Next, we made a modified save file with anything related to Polaroid and Negative disabled.
Tried it, but Polaroid/Negative always unlocked automatically as I was playing. In the end, I realized that as long as we can't prevent either the trap door or the light beam from spawning after Mom's Heart, this change wouldn't really force you to take a certain path anyways (it just denies access to one of the final floors).
You could keep Sheol and Cathedral disabled (they'd still show up on a devil or angel room), but they'd probably pop back up after a run or two.
hey dude nice mod, but just wondering will you be making a rebirth port for this? thnx
That's probably not going to happen, especially since major changes like item rarities and the new final bosses wouldn't work in Rebirth. Sorry.
that's ok, was just wondering. thnx for replying though
Game crashed on Ubuntu when using Book of Belial, just so you know.
Is there way to get to Mega Satan in this mode?
Yes, the Key Master on the final floor will always pay out with Dad's Key.
how did you code item rarities into this?
Item weights already exist in Afterbirth, but are only used to increase the rarity of Mega Blast. They can be changed for every item in the "itempools.xml" file, no coding required.
oh, really? it's incredible how you can learn something new about isaac here and there even after 600+ hours. Thanks
Hey, i wanted to aks you if i could use some of your Floor sprites for my mod. Im very bad at pixeling Sprites but i want to change some floors. You would be credited at the Ingame TitleScreen and in the Files
This mod doesn't include completely new floor sprites (it just switches around existing ones), so no need to credit me for that.
I thought this mod already existed? I remember trying it out a few months ago.
I deleted my previous mod some time ago as I wasn't really happy with it. So yeah, you could see this as the 2.0 version.
This looks great and all, but will the included file override my current save, or create a new one in File 2?
It will replace your third save file. To overwrite another save file instead, you have to change the "3" in "ab_persistentgamedata3.dat" to "1" or "2" respectively before copying it.
Alright, thanks! Initiating download now.
April 10, 2022 - 2 years ago
Hey! We have a new Discord server. You can find more information in the announcements channel there. See you there!