The Binding of Isaac Rebirth: Breaking Cain Guide

The Binding of Isaac: Repentance added “tainted” versions of every character to the game, handily doubling the total character count. One of these characters, Tainted Cain, has a strange gimmick where he cannot pick up any items; instead, they explode into pickups Tainted Cain can use to craft items instead. This gives Tainted Cain an unparalleled level of control over which items he acquires, and with it, the potential to break the game wide open.

The potential of Tainted Cain is incredible. It takes a long time to set a breaking run up, but once accomplished, he can be used to easily win any run and add almost any item to the collection page. This makes him incredibly useful for earning stray achievements.

Tainted Cain is exclusive to The Binding of Isaac: Repentance. If you do not own the Repentance expansion, you obviously will not be able to take advantage of this guide.

• Easily clear any run as himself.
• Use the Clicker to turn into another character and easily clear a run as them.
• Obtain almost any item in the game, thereby adding it to the Collection page for achievement purposes.
• Generate specific item combinations for clearing certain difficult achievements.

• Help you clear Challenges or Daily Runs.
• Acquire certain items not in the crafting catalogue.

If you’re relatively new to The Binding of Isaac, I recommend bookmarking this guide for later and just playing on your own for a while. If you really want to beeline for Tainted Cain, this section will detail how to unlock him as quickly as possible.

Regular Cain can be unlocked by holding at least 55 cents at any time. You will need regular Cain to unlock Tainted Cain.

Unlocking tainted characters is a long process, reserved for the very end of The Binding of Isaac’s unlock order.

1. Defeating Mom in Depths II for the first time will end the game and unlock the Womb.
2. Defeating Mom’s Heart in Womb II ten times will unlock a new area called “???”, also referred to as the Blue Womb. On subsequent playthroughs, defeating Mom’s Heart (or its replacement, It Lives!) before the timer reaches 30:00 will cause a path to the Blue Womb to open up. Here, you will fight a powerful boss named Hush.
3. Defeating Hush three times will cause a new door to appear on subsequent playthroughs whenever you defeat the boss of Basement I. This leads to an alternate set of levels, based on the Antibirth fan mod.
4. Navigating the Antibirth levels is tricky; you may want to look at a separate guide to learn how to acquire the Knife Pieces and reach the Corpse. At the end of the Antibirth path, you will fight Mother. Defeating Mother for the first time will cause a strange door to appear at the beginning of Depths II in all subsequent playthroughs of the regular path.
5. Bring either the Polaroid or the Negative to this door. This will consume the item and unlock the strange door. Note that you normally cannot leave the boss room after defeating Mom; you will need to have some way to teleport out before you go in and fight Mom. Somewhere on the floor you can find a skull with an X-shaped crack in it; breaking it will always reward you with a 0 – The Fool card.
6. Behind the strange door is a hole to a special Mausoleum floor. The boss room contains no boss; only an item, Dad’s Note. Picking it up will begin the Ascent. During the Ascent, you’ll fight your way back up through modified versions of all the previous floors. At the end you’ll reach a special floor called Home. Here, in Mom’s bedroom, you’ll find a chest containing the Red Key, which will also unlock the Red Key for future playthroughs. Using the Red Key on the reddish door outline in the hallway outside Mom’s bedroom will unlock a secret closet containing the tainted version of whichever character you’re playing as. If you’re playing as Cain, you’ll unlock Tainted Cain; if not, you’ll have to do it again as Cain on a later playthrough.
7. The Red Key is not guaranteed to appear in subsequent playthroughs; to unlock subsequent tainted characters, leave any Trinket in a boss room on your way down to Dad’s Note (this can even include the “boss” room containing Dad’s Note). During the Ascent, those Trinkets will get transformed into a Cracked Key, a single-use consumable version of the Red Key. You can bring this Cracked Key up to Home to unlock more tainted characters.

Tainted Cain cannot craft items you have not unlocked yet; their recipes will instead just give you Breakfast.

Depending on how you intend to break the game, you may require some of the following items.

If you intend to break the game in the regular mode, you will require the  D1. This can be unlocked by completing Greedier Mode as Isaac. Note that Greedier Mode itself must be unlocked by donating a total of 500 cents to the Greed Donation Machine in regular Greed Mode, if you haven’t done that yet. Ironically, despite its connection to Greed Mode, you do not need the D1 to break Greed Mode.

 Birthright is mandatory for breaking Greed Mode, and very useful (though not mandatory) for breaking the regular mode. It can be unlocked by completing the Chest as Jacob & Esau, who are themselves unlocked by clearing the Corpse for the first time.

All other necessary items are available by default.

If you already know how to play as Tainted Cain and are just looking for how to break the game as him, you may skip this section.

Tainted Cain is tricky. Whenever he tries to pick up an item pedestal, the item will explode into pickups such as Pennies, Keys, Bombs, and Red Hearts. The only items exempt from this are certain “story” items such as the Polaroid, the Negative, Dad’s Note, ect.

Tainted Cain starts out with a Bag of Crafting permanently in his consumable slot. If you pick up a regular consumable, such as a Pill or Card, you can switch between it and the bag by tapping the drop consumable key (Ctrl by default).

Tapping the key to use your consumable (Q by default) while the Bag of Crafting is chosen will let Tainted Cain pull his bag out, and pressing an attack key after that will swing the bag in that direction. Swinging the bag at pickups will scoop them up into the bag. The currently held pickups can be seen next to the Bag of Crafting. They cannot be spilled out of the bag; once an item is scooped into the bag, for all intents and purposes it’s been destroyed, so think twice before scooping. Besides every variety of coin, heart, key, and bomb, you can also scoop up Cards, Pills, Runes, and batteries. Different battery sizes are treated as different ingredients, but different types of Cards, Pills, and Runes are all interchangeable.

The bag can hold up to eight pickups. Once you have eight, an item will be displayed next to the Bag of Crafting to display what item will be produced with those ingredients. By holding down Q, Tainted Cain will take some time to make the item; once done, you will acquire the listed item.

If you scoop up pickups while you already have eight items in the bag, the pickup in the top-left corner will be destroyed and replaced with the new pickup. You can rotate which pickup is in the top-left slot by tapping Ctrl.

If Tainted Cain crafts an Active Item while he already has an Active Item, the old Active Item will immediately explode into pickups to make room for the new one. Be cautious, there’s no way to undo this short of re-crafting the old item.

Normally, the types of pickups released from a burst item pedestal are a fairly random assortment of common pickups, but bursting an item pedestal in certain rooms will always produce certain results:

• Item pedestals in Angel Rooms will always drop an Eternal Heart.
• Item pedestals in Devil Rooms will always drop a Black Heart.
• Item pedestals in Secret Rooms and Super Secret Rooms will always drop a Bone Heart if they’re unlocked.
• Item pedestals in Curse Rooms will always drop a Rotten Heart if they’re unlocked.

Using the above-mentioned fact that newly crafted Active Items will destroy your previously held Active Item, you can exploit this to force rare types of hearts to spawn. Note that other room types, including Planetariums, Shops, and Boss Rooms, are not guaranteed to drop anything out of the ordinary.

Breaking the regular game and breaking Greed Mode follow two different methods. This section will focus on the regular game. You can skip this if you intend to break Greed Mode.

As you play, try to avoid picking up any pickups unless absolutely necessary (Hearts to heal yourself, Keys to unlock doors, ect.). Leave them laying on the ground until you’ve completed every room on the floor.

Your first goal is to craft the  D1; not only is it necessary for the break itself, it’s also just extremely useful for setting things up to begin with.

The easiest recipe for the D1 is:

• 5 Red Hearts
• 1 Penny
• 1 Nickel
• 1 Pill

If you cannot find any pills, an alternative recipe is:

• 4 Bombs
• 1 Penny
• 2 Nickels
• 1 Key

It is unlikely you will assemble the full recipe on Basement I; once you’ve scooped up all the ingredients you can for the D1, you can carry them to Basement II and try again for the remaining ingredients. Don’t forget to collect any stray pickups you avoided before leaving the floor; after all, if you aren’t going to use them for crafting, you might as well just collect them the old-fashioned way so you have some Pennies, Keys, and Bombs for later.

You should hopefully be able to complete the D1 recipe on either Basement II or Caves I; if you have to go deeper than that, you may want to just reset and start over before the game gets too hard to survive without useful items.

Once you have the D1, it can be used to create a duplicate of any pickup in the room. The duplicated pickup is random; the only way to guarantee duplicating the pickup you want is if it’s the only pickup in the room.

Your next step is to create the  Car Battery

The easiest recipe is probably:

• 2 Soul Hearts
• 3 Bombs
• 1 Penny
• 1 Key
• 1 Card

Now that you have the D1, you can use it to help make the Car Battery. Use it to duplicate rare resources such as Soul Hearts before scooping them up.

The Car Battery doubles the effect of your Active Item. In the case of the D1, that means every time you use the D1, it will produce two additional copies of a pickup in the room.

Your next step is to find either a Lil’ Battery or Charged Key.

The most likely place to find a Lil’ Battery is the shop, which may be selling them. You may also be lucky enough to simply find one laying around as a room reward clear, or find a  48 Hour Energy! Pill which will generate several Lil’ Batteries on use.

If you cannot find any Lil’ Batteries naturally, you can generate one by crafting the  Battery Pack.

• 4 Red Hearts
• 3 Pennies
• 1 Key

Besides recharging your Active Item, it will also spawn several random batteries around you. If you must rely on the Battery Pack for generating a battery, I recommend crafting it in a room around the center of the map, rather than out on the fringes; you’ll be visiting this room often. Destroy any Micro Batteries by scooping them up, and leave only the full-sized Lil’ Batteries.

Note that once you find or make a Lil’ Battery, the floor you’re currently on will be your base for the next hour or two; if it has any extremely annoying rooms you’ll have to run through frequently or a really uncomfortable layout, you may consider going deeper to the next floor, but don’t push your luck by going too deep. Having a Curse Room is also desirable, if the floor has it. Note that floor curses and excess spikes are tolerable; you’ll be able to remove those soon.

Now that you have a Lil’ Battery sitting on the floor, use the D1 to duplicate the Lil’ Battery. A single Lil’ Battery will recharge your D1, and using the D1 will generate two Lil’ Batteries due to the Car Battery. Congratulations, you’ve officially broken the game; you now make Lil’ Batteries faster than you consume them, allowing you to use the D1 infinitely as long as you keep a healthy stock of Lil’ Batteries. I recommend spamming the D1 in your battery room for a while until most of the room is filled with Lil’ Batteries, just so you don’t accidentally run out. From here on out, I will be referring to this as the battery room.

You can also use Charged Keys instead of Lil’ Batteries, but keep in mind charged keys get picked up no matter what when touched, whereas Lil’ Batteries get pushed away if you have a full charge; this makes them less optimal than Lil’ Batteries.

Due to how the D1 works, you’ll want to have dedicated rooms for each resource; just as you have a battery room, you’ll want a Red Heart room, a Penny room, ect. There should still be some pickups and items scattered around the floor, so you can use those to start setting up your rooms. Commonly requested resources such as Pennies, Nickels, Bombs, Keys, Red Hearts, and Soul Hearts should preferably be built close to the battery room, to minimize travel time. More exotic resources can be kept further away.

Just like your batteries, try to keep a healthy stock of each resource type; spam the D1 on them a few times. You don’t want to accidentally run out of a resource and have none left to duplicate, or accidentally destroy your D1 and be unable to rebuild it because you didn’t leave enough Nickels or Pills.

You probably don’t have one of every pickup just sitting around on the floor, however. We will discuss that in an upcoming section of the guide.

Breaking the regular game and breaking Greed Mode follow two different methods. This section will focus on Greed Mode. You can skip this if you intend to break the regular game.

As stated, breaking Greed Mode (and Greedier Mode) works a little differently from breaking the regular game. Instead of using the D1 to make duplicates of pickups, you’ll just be making tons and tons of random pickups and sifting through them for useful ones.

The first order of business is crafting a  Steam Sale for yourself. The easiest recipe is:

• 4 Pennies
• 1 Red Heart
• 2 Keys
• 1 Bomb

Tainted Cain starts with a key in his inventory so he has access to both the gold item room and the silver item room. Touch the item pedestals in both to make them burst into pickups; if you don’t get enough to craft the Steam Sale from those two (plus any loose pickups sitting in the shop, if you want to investigate that), just hold R and reset the run. Keep trying until you are able to make a Steam Sale before doing anything else.

Now all items in the shop are half-off, with collectibles being 7 cents instead of 15 cents. Play the first floor of Greed Mode to amass some more Pennies for yourself; you should be able to buy an item or two now.

Eventually you’ll want to make three more Steam Sales to reduce the price of all shop items to a measly 3 cents. However, before making more Steam Sales you will probably need to make Birthright. Don’t be afraid to proceed to the next floor for more resources. If the first floor shop is selling pills, buy one before going on, however.

 Birthright is critical here in Greed Mode; without it, you won’t be able to sustain yourself. The most basic recipe is:

• 4 Bombs
• 3 Pennies
• 1 Pill

Pills are tricky to come by. If the shop isn’t selling Pills, you should try paying the Restock Machine until a Pill appears. This isn’t guaranteed to work, however, and you may wind up having to reset the run if you’re unlucky.

Now that you hopefully have Birthright, all item pedestals will explode into more pickups than usual when touched. Try and craft those extra Steam Sales now if you can. You may notice now that it only costs 3 cents to buy the infinitely-restocking items, yet they almost always explode into more than 3 cents. Congratulations, you’ve officially broken the game. Keep buying items to generate more pickups, including more money to buy items with.

Some pickups are rarer than others; you may have to buy many items before one shows up. The room will gradually fill more and more with excess pickups such as Red Hearts, Keys, and Bombs. If you need to clear these out, just scoop ’em up with your Bag of Crafting; you might even randomly stumble upon a useful crafting recipe in the process. Occasionally you’ll get a Troll Bomb or worse, a Golden Troll Bomb. We can deal with those eventually, hopefully before they become a problem.

While getting ahold of Red Hearts, Keys, Pennies, and other common pickups is easy, some pickup types are rarer. Maybe you got lucky and were able to find one of every useful pickup on the floor. Chances are you weren’t, and will need to manually force a few to spawn. This section of the guide will talk about how to generate each type of resource, usually by crafting items.

Speaking of crafting, I will not be providing crafting recipes going forward. You can find a useful archive of crafting recipes here at the Platinum God website

[platinumgod.co.uk]. Even more crafting recipes can be found on the Binding of Isaac: Rebirth Wiki here[bindingofisaacrebirth.fandom.com], but due to how massive the list is it is slower and less convenient and should primarily be used if you don’t like any of the recipes listed on Platinum God.

Giga Bombs, Mega Batteries, Dice Shards, and Cracked Keys can technically be picked up with the Bag of Crafting, but on top of being prohibitively rare they are not necessary for any crafting recipes and will be ignored in this guide.

If you need to generate a large amount of random pickups and don’t care which types, some of the following can help:

• Chests will pay out with pickups, and can be duplicated before opening with the D1. This is the most reliable way to get Gold Hearts, Golden Bombs, Golden Keys, and Charged Keys outside of Greed Mode.
•  The D20 (Unlocked by clearing the Chest as Isaac) can reroll all pickups in the room randomly. Remember not to destroy your D1 by crafting this.
•  The Everything Jar (Unlocked by defeating The Beast as Eden) can be used to generate a very wide variety of pickups based on its charge level. However, reaching specific charge levels is difficult without rooms to fight enemies in.
•  The Box will generate several random pickups when crafted, including a Card or Rune, and a Pill.
•  VIII – Justice will generate a Red Heart, a Penny, a Bomb, and a Key on use.
•  X – Wheel of Fortune, XIV – Temperance, and XX – Judgement will generate a Slot Machine, Blood Donation Machine, or Beggar respectively, all of which may pay out with pickups if interacted with or blown up.
•  VIII – Justice? (Unlocked by clearing Challenge #43) will generate Golden Chests which can pay out with pickups.

Red Hearts are one of the more common items in the game; chances are you already have some sitting around on the floor, or can make some more by bursting an item pedestal.

Half Red Hearts are fine to use, and will count as a whole Red Heart in crafting. Double Red Hearts should not be used, as they count as two Red Hearts and can make certain recipes difficult or impossible to make.

Note that Blended Hearts will grant you both a Red Heart and a Soul Heart when scooped up, so you should not rely on them for crafting if you can get access to regular Red Hearts and Soul Hearts.

•  Marrow will generate three Red Hearts when crafted. It is unlocked by clearing Womb II on Hard Mode as The Forgotten.
•  Mr. Dolly will generate three hearts that can randomly be Red, Soul, or Black Hearts.
•  VI – The Lovers will generate two Red Hearts on use, but you will need a way to generate cards first if you don’t have one sitting around.
•  Queen of Hearts (Unlocked by defeating Mega Satan with Tainted Magdalene) will generate a massive amount of Red Hearts.
•  Hematemesis will generate several Red Hearts.

Soul Hearts are rarer to find than Red Hearts, but are an extremely common ingredient in crafting powerful items. Some recipes even call for five or six Soul Hearts. You will want a steady supply of them.

Half-Soul Hearts are fine, and will count as a whole Soul Heart in crafting.

Note that Blended Hearts will grant you both a Red Heart and a Soul Heart when scooped up, so you should not rely on them for crafting if you can get access to regular Red Hearts and Soul Hearts.

•  Squeezy will generate two Soul Hearts when crafted.
•  Mr. Dolly will generate three hearts that can randomly be Red, Soul, or Black Hearts.
•  Mom’s Pearl has a chance of replacing new Red Hearts with Soul Hearts. This is more useful in Greed Mode, where making item pedestals explode into pickups generates many new hearts.
•  V – The Hierophant will generate two Soul Hearts on use, but you will need a way to generate cards first if you don’t have one sitting around.

Black Hearts are used to craft items from the Devil Room pool.

Bursting an item pedestal in a Devil Room will always generate a Black Heart, but due to the fleeting nature of Devil Rooms this is not a reliable way to farm Black Hearts unless you have an item that can keep the Devil Room open, or find a Devil Room using the Red Key.

•  Mr. Dolly will generate three hearts that can randomly be Red, Soul, or Black Hearts. This is one of the few ways to semi-reliably generate Black Hearts outside of a Devil Room.

Eternal Hearts are used to craft items from the Angel Room pool.

Bursting an item pedestal in an Angel Room will always generate an Eternal Heart, but due to the fleeting nature of Angel Rooms this is not a reliable way to farm Eternal Hearts unless you have an item that can keep the Angel Room open, or find an Angel Room using the Red Key.

•  Sworn Protector generates an Eternal Heart if it blocks ten enemy projectiles in a single room. Unlocking it is an ordeal, as it requires you defeat Hush as The Lost, but it is one of the few ways to force an Eternal Heart to spawn. You may need to use the Red Key or D7 to find new enemies capable of firing projectiles at you.

Gold Hearts are used to craft items from the Golden Chest pool. Note that Gold Hearts themselves must first be unlocked by clearing Challenge #21.

Unfortunately, there is no reliable way to generate Gold Hearts. Your best chance in the regular mode is to use the D1 to duplicate many chests and open them. It is easier to get Gold Hearts in Greed Mode due to the availability of endless item pedestals.

•  The Everything Jar (Unlocked by defeating The Beast as Eden) generates a Gold Heart when used at 9 charges, but reaching that exact level may prove difficult or even impossible.

Bone Hearts are used to craft items from the Secret Room pool. Note that Bone Hearts themselves must first be unlocked alongside The Forgotten.

Getting Bone Hearts is fairly easy; making an item pedestal burst in a Secret Room or Super Secret Room will always generate a Bone Heart. Note, however, that Super Secret Rooms that force a specific heart type to spawn (such as the Womb-style rooms full of Red Hearts) will override this. If for some reason you don’t have access to a Secret Room or Super Secret Room, there’s only one other way to force a Bone Heart to spawn.

•  V – The Hierophant? (Unlocked by clearing Greedier Mode as Tainted Bethany) will generate two Bone Hearts on use, but you will need a way to generate cards first if you don’t have one sitting around.

Rotten Hearts are used to craft items from the Curse Room pool. Note that Rotten Hearts themselves must be unlocked by entering the Corpse for the first time.

Getting Rotten Hearts is fairly easy if the floor you’re on has a Curse Room; making an item pedestal burst in a Curse Room will always generate a Rotten Heart. If you do not have a Curse Room available, then the only other way to get Rotten Hearts is to pray you get lucky with an item pedestal or a chest, or manage to spawn a Rotten Beggar using .XX – Judgement.

Coins are somewhat different from other pickups in that most items that force coins to spawn have completely randomized results; there is no way to specifically force a Penny, Nickel, or Dime to spawn, for example. The following items can be used to spawn random denominations of coins.

•  Pageant Boy will generate several random coins.
•  Keeper’s Sack (Unlocked by clearing the Corpse as Keeper) will generate three random coins and a Key.
•  Soul of the Keeper (Unlocked by defeating Boss Rush and Hush as Tainted Keeper) will generate a large amount of random coins.

Pennies are a very common resource, and can be found sitting around in most locations. Greed Mode always rewards you with Pennies for clearing waves, and you can bomb the shop donation machine if you’re really desperate.

Double Pennies should not be used, as they count as two Pennies when scooped up and can make certain crafting recipes difficult or impossible to make. Golden Pennies are acceptable, as they simply count as regular Pennies in crafting.

Nickels are rarer to find than Pennies. Many crafting recipes call upon Nickels, so having them available is important.

Most ways of forcing coins to spawn have a chance of spawning Nickels.

Dimes are even rarer than Nickels. Thankfully, few crafting recipes require them.

Most ways of forcing coins to spawn have a very slim chance of spawning Dimes.

Lucky Pennies are a rare type of coin. They must be unlocked first by donating 1 cent to the Greed Donation Machine. Many of the most powerful items in the game require a Lucky Penny in their crafting recipes.

Most ways of forcing coins to spawn have a prohibitively small chance of spawning Lucky Pennies, which make them very difficult to spawn. There is one item that can specifically force a Lucky Penny to spawn, however:

•  Dad’s Lost Coin (Unlocked by clearing Greedier Mode as The Lost) will generate a Lucky Penny when crafted. This is the only guaranteed way to spawn a Lucky Penny, though unlocking the item is very difficult.

Bombs are a common resource.

Double Bombs should not be used, as they count as two Bombs when scooped up and can make certain crafting recipes difficult or impossible to make.

•  Match Book will generate several Bombs when crafted.

Golden Bombs are a rare version of Bombs unlocked by clearing Challenge #23.

Unfortunately, there is no reliable way to generate Golden Bombs. Your best chance in the regular mode is to use the D1 to duplicate many chests and open them. It is easier to get Golden Bombs in Greed Mode due to the availability of endless item pedestals.

•  The Everything Jar (Unlocked by defeating The Beast as Eden) generates a Golden Bomb when used at 11 charges, but reaching that exact level may prove difficult or even impossible.

Keys are a common resource.

Key Rings should not be used, as they count as two Keys when scooped up and can make certain crafting recipes difficult or impossible to make.

•  Latch Key will generate two Keys when crafted.

Golden Keys are a rare version of Keys.

Unfortunately, there is no reliable way to generate Golden Keys. Your best chance in the regular mode is to use the D1 to duplicate many chests and open them. It is easier to get Golden Keys in Greed Mode due to the availability of endless item pedestals.

•  The Everything Jar (Unlocked by defeating The Beast as Eden) generates a Golden Key when used at 10 charges, but reaching that exact level may prove difficult or even impossible.

Charged Keys are a rare version of Keys unlocked by clearing Challenge #33.

Unfortunately, there is no reliable way to generate Charged Keys. Your best chance in the regular mode is to use the D1 to duplicate many chests and open them. It is easier to get Charged Keys in Greed Mode due to the availability of endless item pedestals.

Micro Batteries are the smallest type of battery. Golden Batteries count as Micro Batteries for crafting purposes.

•  Battery Pack generates several randomly sized batteries when crafted.

Despite the name, Lil’ Batteries are the full-sized batteries. If you’ve made it this far you should already have a room full of them; indeed, some crafting recipes make use of them, so your battery room may serve an additional purpose.

•  Battery Pack generates several randomly sized batteries when crafted.

Pills are a moderately rare consumable. Note that all Pills are the same in crafting, regardless of their color and effect. Horse Pills and Golden Pills can be used too, and count the same as a regular Pill.

•  PHD will, in addition to making all Pills positive, generate one Pill upon being crafted.
•  Mom’s Coin Purse will generate several Pills upon being crafted.
•  Mom’s Bottle of Pills can be used to generate as many Pills as desired, but as an Active Item you must be careful not to destroy your D1 with it.
•  Polydactyly will generate a random Pill, Card, or Rune when crafted.

Cards are a moderately rare consumable. Note that all Cards are the same in crafting, regardless of their type. Emergency Contact counts as a Card.

•  Booster Pack will generate three random Cards when crafted.
•  Magic 8 Ball will generate a Card upon being crafted.
•  Deck of Cards can be used to generate as many Cards as desired, but as an Active Item you must be careful not to destroy your D1 with it.
•  Tarot Cloth will generate a random Card or Rune when crafted.
•  Polydactyly will generate a random Pill, Card, or Rune when crafted.

Runes are a moderately rare consumable used to craft items from the Planetarium pool. Note that all Runes are the same in crafting, regardless of their type. Soul stones also count as Runes.

•  Rune Bag generates a Rune after clearing several rooms. It is unlocked by clearing the Cathedral as Lilith. This is the only reliable way to force a Rune to spawn, but you may need to craft the Red Key or D7 in order to have enough rooms to get a Rune.
•  Tarot Cloth will generate a random Card or Rune when crafted.
•  Polydactyly will generate a random Pill, Card, or Rune when crafted.

Besides generating more resources, some items are simply useful to have during the breaking process. They might not kill every enemy you meet or help you melt Delirium to sludge in record time, but they’re all useful nonetheless.

This section of the guide will talk about items that are useful to craft early on, not because they make you powerful but because they make things more convenient while you’re still trying to break the game. We’ll talk about powerful item synergies later.

•  Schoolbag allows you to carry two Active Items at once, and switch between them by tapping Ctrl. It can be unlocked by entering all six shops from Basement I to Depths II in a single run. This is extremely useful (almost mandatory, even) for breaking the main game, as it allows you to keep your D1 while still using other useful Active Items. It is less important in Greed Mode, but it never hurts to have. Remember that when you craft a third Active Item, whichever of the two old items is currently selected is the one that’ll explode into pickups; make sure it’s not the D1.
•  With a crafting recipe of 8 pennies, Portable Slot is one of the simplest and easiest crafting recipes in the game. While you can use the slot itself if you like, the main reason to craft it is as a quick and easy way to destroy your current Active Item (preferably not the D1) and spawn pickups in whatever room you desire. This lets you force Eternal Hearts, Black Hearts, Bone Hearts, and Rotten Hearts to spawn if you do this in the appropriate room type.

These items will help make the current floor you’re situated on more tolerable to navigate.

•  The Black Candle will provide you immunity to floor curses, including any on the current floor. It is unlocked by donating 150 cents to the shop donation machine. If the floor you’re using as your base has an annoying curse like Curse of Darkness or Curse of the Blind, you’ll want to craft this as soon as possible.
• Any source of flight; the easiest to make without rare ingredients is  Transcendence, which requires easy-to-acquire Bone Hearts and is unlocked just by clearing Womb II three times. If you have access to Eternal Hearts, Black Hearts, or Gold Hearts, you can try making other flight-granting items such as Lord of the Pit, Spirit of the Night, Dead Dove, Holy Grail, Revelation, or Fate.
•  The Mind is difficult to unlock, requiring you clear Sheol as The Lost, but it reveals the entire map and all Secret Rooms. If you do not have The Mind unlocked, you can simulate its effect with the Treasure Map, Blue Map, and The Compass combined.
•  The Red Key lets you generate new rooms outside the normal map. It is unlocked when you open the chest in Mom’s bedroom for the first time at the end of the Ascent. It is very helpful for breaking the game, as it allows you more rooms to store your pickups, and can lead to hidden Angel Rooms and Devil Rooms which can be used to reliably generate Eternal Hearts or Black Hearts if you weren’t able to generate them otherwise.

Trinkets are useful too! If you’ve got room for an Active Item, you can create and then permanently smelt any Trinket in the game onto yourself.

•  Mom’s Box is an Active Item that generates a new Trinket every time it’s used. With infinite batteries you should be able to use Mom’s Box infinitely and generate every single Trinket in the game. You’ll know you have when you start generating duplicates. I recommend setting aside a large, otherwise-empty room specifically for storing all your generated Trinkets until you’re ready to smelt them.
•  The Smelter is an Active Item that consumes your current Trinket and makes it permanent. It is unlocked by clearing Womb II on Hard Mode as Apollyon. If you’ve generated every Trinket in the game with Mom’s Box, you can now also smelt every Trinket you want. Be cautioned that some Trinkets are detrimental to breaking the game and should not be held, let alone smelted; more on that later. Also remember you cannot hold the D1, Mom’s Box, and the Smelter all at the same time, even with the Schoolbag; be careful not to destroy your D1 if you’re doing this in the regular game.
•  Mom’s Purse and  Belly Button both allow you to carry two Trinkets at once, doubling the rate at which you can smelt Trinkets onto yourself. Note that they do not stack; even with both, you’re limited to carrying two Trinkets at a time.

•  The Battery allows you to to hold two full charges on your Active Items. This won’t help you acquire anything you couldn’t get otherwise, but it is an immense time-saver that lets you use the D1 twice without returning to the battery room.
•  PHD makes all Pills positive, which can be used with the D1 to consume large amounts of beneficial pills.
•  Polydactyly will allow you to carry two consumables of any type (Cards, Pills, Runes).
•  The Paper Clip allows you to open Golden Chests without spending Keys. This can be very convenient if you’ve been mass-duplicating Golden Chests with the D1.
•  The Moving Box can be used to move pickups or item pedestals from one room to another. It can be unlocked by using Pandora’s Box in the Dark Room. You may find this useful if you have some pickups in a faraway room you want to move to a closer room.

•  Counterfeit Penny (Unlocked by playing the Shell Game 100 times) will sometimes grant you extra money when you pick up coins. You have access to infinite money, but that doesn’t mean you can’t speed things up by holding this Trinket.
•  Deep Pockets increases your maximum coin count to 999. It is unlocked by clearing the Chest as Keeper. Money probably won’t be an issue, but it does give you a bigger wallet for when you want to buy many expensive items from a shop or donate massive amounts of leftover money to donation machines.
•  Restock will make shops continuously replace purchased items, albeit at higher prices. This is unnecessary in Greed Mode.
•  Member Card, unlocked by spending 40 cents in a single shop, grants access to a special basement in each shop that contains additional items. Besides having more item pedestals to burst into pickups, the basement shop may also sell rare items such as Runes.

•  Holy Mantle is always one of the best items in the game, and here is no exception; besides being useful later on in the run, it will also allow you to avoid taking damage when venturing in and out of the Curse Room if you haven’t filed the spikes off yet.
•  Pyromaniac is another item that, besides being amazingly powerful later, will also help during the breaking process, protecting you from random explosions due to Troll Bombs or potentially your own bomb placements.
•  Safety Scissors will defuse any Troll Bombs. This is extremely useful and extremely important in Greed Mode, where Golden Troll Bombs will wreak havoc endlessly if spawned from an item pedestal.
•  Flat File will remove all spikes from the floor, spiky rocks, and even the Curse Room door, allowing safe access. Note that this will also make Sacrifice Rooms permanently unusable if you smelt the Flat File, so think twice before doing that.

Some items can impede your ability to properly break the game. Try to avoid crafting these items. Some Trinkets are problematic as well, and should not be smelted permanently into your inventory.

•  Butter! should be avoided at all costs; its effect can cause Tainted Cain to drop his Bag of Crafting, permanently losing the ability to craft items.
•  Error grants you a random Trinket effect each room, which can potentially include undesirable effects such as the aforementioned Butter! or other problematic Trinkets. It can be difficult to notice this Trinket laying on the ground, so be careful not to accidentally pick it up while smelting.
•  Humbling Bundle,  Equality!, and  Bogo Bombs will cause certain pickups to become their doubled versions. This can make it difficult to get an odd number of them in your Bag of Crafting.
•  Little Baggy and  Starter Deck will turn all cards into pills or all pills into cards, respectively. Do not craft these unless you are willing to craft both of them. You’re better off just crafting Polydactyly.
•  Bum Friend,  Dark Bum,  Key Bum, and  Bumbo should be avoided, as they will steal the pickups you have laying on the ground. Do not craft any of these unless you are absolutely certain you will not require their preferred pickups anymore.
•  Cursed Penny teleports you every time you pick up a coin. As you’ll be touching many coins (especially in Greed Mode), this effect will become aggravating very fast.
•  Broken Remote,  ‘M, and  Expansion Pack will cause undesirable effects when using your Active Item, making it very difficult to use the D1 for pickup duplication.
•  Magneto,  Broken Magnet, and  Super Magnet will pull pickups toward Isaac, potentially collecting them when you don’t want to.
•  GB Bug and  Lil Portal can potentially reroll or consume pickups if mismanaged.
•  Missing No. will reroll all your items every floor transition potentially ruining the entire purpose of your playthrough.
•  TMTRAINER will not directly impact Tainted Cain’s crafting but will render most runs unfinishable due to corrupting plot-critical items such as the Negative and Polaroid.
•  Avoid Vanishing Twin if you intend to go down the Antibirth alternate levels; encountering the Great Gideon boss with Vanishing Twin will softlock the game.
•  Filigree Feather will prevent Angels from dropping Key Pieces. Only smelt this Trinket if you’re certain you do not intend to fight Mega Satan.
•  Bloody Penny,  Burnt Penny,  Flat Penny, and  Blessed Penny can be mildly inconveniencing, by spawning foreign pickups when you collect coins. This isn’t always a problem, and Blessed Penny can even help out if you can’t find Soul Hearts, but I do not recommend smelting them if you still have work to do. Note that Counterfeit Penny does not have this problem, as it directly adds extra coins to your inventory instead of spawning them on the floor.
• Too many Range Up upgrades, be they items or pills. Believe it or not, Tainted Cain’s Bag of Crafting works off the range stat, and the higher your stat the further in front of you the Bag of Crafting’s hitbox will be. If you upgrade it too much, you’ll have trouble scooping up pickups.
• While not caused by any one specific item, avoid item combinations that can cause a game crash, such as numerous processor-taxing flashy tear effects combined with a high rate of fire.
• This goes without saying, but obviously do not craft items or smelt Trinkets that you would not want to put up with later in the game; just about everything you make here is permanent, after all.

Now that you’re capable of crafting any item in the game, it’s time to get down to business. Consider why you’re breaking the game, and decide what you want to do with this power at your fingertips. The upcoming sections of the guide will walk you through accomplishing any of these goals.

• Make yourself absurdly powerful.
• Clear almost all of Tainted Cain’s completion marks in one run.
• Clear another character’s completion marks.
• Exploit Eden’s Blessing to make your next run start strong.
• Generate items missing from your item catalogue.
• Generate specific items needed for achievements.

If you aren’t just making items for your collection page or specific achievements, you probably want to become strong. This section will help you become the most powerful Tainted Cain (or other character!) you can be.

Be careful not to go too overboard on item synergies and flashy tear effects; you can potentially cause the game to crash just from trying to fire tears, and nobody wants that.

Making yourself utterly invincible is a good way to break the game. I recommend crafting several or even all of the following items, especially if you intend to use the Clicker to turn yourself into a fragile or difficult character such as Tainted Lost, Tainted Keeper, or Tainted Jacob.

•  Holy Mantle was already discussed earlier, but if you haven’t made it yet you may as well make it now. This is especially powerful if you intend to become Tainted Lost, who otherwise cannot obtain the Holy Mantle.
•  The Wafer reduces all damage sources down to just half a heart of damage. In the Womb and beyond, this means you basically have double the health you’d normally have, assuming you even take any damage to begin with.
•  Pyromaniac was also discussed earlier. Not only does it make you immune to explosions, it also heals you when you get blown up. If your character has Red Hearts, you can potentially make yourself invincible by pairing this item with Kamikaze or Dr. Fetus, but even just the explosion immunity on its own makes the game much easier.
•  Dead Cat will grant you nine additional lives, at the expense of removing all but one of your Red Hearts; this isn’t a problem, though, because you should have infinite Soul Hearts sitting around, and can just craft more health-granting items if desired. You can actually make as many Dead Cats as you like and gain even more lives. This item is very useful if you intend to become Tainted Lost, who otherwise has trouble finding extra lives, but it is not very useful as Tainted Eden, who will probably lose the Dead Cat if they get hit anyway.
•  Psy Fly is a potent shield, intercepting any enemy projectiles launched your way. Remember that it cannot protect you from enemy Brimstone beams or certain other non-conventional attacks.
•  2Spooky will make nearby enemies suffer the Fear status and automatically run away from you. It won’t help much against bosses, but it will practically guarantee immunity to contact damage from regular enemies, and is especially good paired with the aforementioned Psy Fly.
•  Lost Contact makes your tears destroy enemy tears on collision. Pairing it with piercing tears, Brimstone, or Tech X lets you destroy a large swathe of incoming fire.
•  Gnawed Leaf grants you total invulnerability as long as you stay still and don’t attack. Pairing it with an auto-attacking familiar (Daddy Long Legs would be the best in this case) can guarantee a victory, but it’s also incredibly slow.
•  Stop Watch permanently slows down all enemies and their projectiles to 80% speed. Unlocking it requires you donate the maximum of 999 coins to the Shop Donation Machine.
•  Evil Charm grants immunity to status conditions. These aren’t common, but the best asset it provides is immunity to the toxic gas often encountered in the Corpse or when fighting Ultra Pestilence. It also protects you from Dogma’s Godhead tears’ auras.
•  Blind Rage greatly increases the duration of mercy invincibility you get after taking damage. It won’t help you as characters who cannot take damage at all, such as Tainted Lost, but it will help everybody else avoid taking more than one stray hit at a time.
   Book of Shadows and  4.5 Volt together allow you to achieve total invincibility; Book of Shadows makes you invincible for 30 seconds (or 60 with the Car Battery), while the 4.5 Volt allows you to recharge the book by dealing damage to enemies. With a powerful build, you’ll deal damage fast enough to stay permanently invincible during long boss battles such as Delirium or Mother. This is especially potent as Tainted Lost.

Let’s be real here, everybody has their preferred synergies and powerful items. Instead of listing every single good item in the game, I will list the items I personally like to use, and the order in which I craft them. You are free to experiment with your own setups.

•  Rock Bottom is a good way to start any powerful build, as it prevents your stats from ever going down, only up. Note that the exact way Rock Bottom works is a little more complicated than that, but if you follow this order you should be fine. Bear in mind you must first unlock Rock Bottom by clearing Boss Rush as Jacob & Esau
•  The Book of Belial will be our main source of damage upgrades, believe it or not. Instead of wasting our time crafting damage-ups like Cricket’s Head or Polyphemus one at a time, we’re going to shoot right for the top. Go to your battery room (or make a battery room, if you’re playing Greed Mode), use the D1 to produce an absolute tidal wave of Lil’ Batteries, then switch to the Book of Belial and start spamming it without leaving the room. If you run low on batteries, just make more. Your damage stat will keep increasing and increasing endlessly, as high as you want it to go; I find a value around 100 to be sufficient. Because of Rock Bottom, our damage will stay this high, instead of falling back down when we leave the room.
•  Even with the nerfs it received in Repentance, Tech X is still one of the best tear replacements in the game. It will serve as the basis of our combo.
•  Brimstone is next, and you can actually craft a second Brimstone if you want your Tech X + Brimstone shots to be thicker.
•  Soy Milk synergizes with Tech X. Now instead of having to charge up shots, simply holding down the fire button will let you release an endless barrage of rings, all with 100+ damage; Rock Bottom nullifies Soy Milk’s massive damage down.
•  Mutant Spider will take our already-broken Tech X barrage and quadruple it with no downside thanks to Rock Bottom. You can craft a second Mutant Spider if desired, for even more shots.
•  Spoon Bender or any other source of homing tears will help curve the beams toward enemies. It is hardly necessary at this point since your shots should be filling the entire room anyway, but it doesn’t hurt.
•  Terra allows your shots to destroy all obstacles in the room, reducing the need for Bombs.
•  Uranus grants a freeze effect to your shots, turning killed enemies into ice statues. The main benefit of this is that it prevents enemies from doing anything bothersome in their death animations, such as splitting into smaller enemies, exploding, or releasing shots. It also makes your rings look cool, figuratively and literally.
•  Holy Light gives your tears a chance to summon powerful beams of light. With a high Luck stat, you’ll summon constant beams of light that’ll absolutely shred apart anything that doesn’t already get vaporized by the Tech X shots alone.
•  If you’re playing Greed Mode, craft Midas’ Touch. It has a secret secondary effect of piercing Ultra Greed’s boss armor.
•  Believe it or not, the Trinket A Lighter can be ludicrously powerful if you were able to get your luck stat to 40 or higher by duplicating Luck Up Pills or Lucky Pennies. It should instantly kill all non-boss enemies the moment you enter any room.

This should be more than sufficient for defeating every enemy and boss in the game, but you can always stack more tear effects on top with items such as Sinus Infection or Jacob’s Ladder. Remember that regular status effects, such as poison tears from Scorpio or fear tears from Dark Matter, have little effect on bosses, and every regular enemy should get pulped immediately by your shots (or A Lighter), making them somewhat superfluous.

Now that you’re powerful and durable enough, it would be useful if you could navigate future floors with little inconvenience. These items should help you figure out where you’re going. This is not as critical in Greed Mode.

•  The Mind, unlocked by clearing Sheol as The Lost, will reveal the full map of every floor, including special rooms and secret rooms. With this, you can beeline for the exit of each floor, or take your time exploring every nook and cranny; the choice is yours. This item was mentioned before, but bears repeating. If you don’t have this unlocked, Treasure Map, Blue Map, and the Compass grant its effect when combined.
•  Black Candle grants immunity to floor curses, such as Curse of the Lost, Curse of the Maze, and Curse of Darkness; you may have already crafted this one too.
• Any flight-granting item. We’ve been over this one before as well. Why wouldn’t you want to fly all the time?
•  Rib of Greed will prevent future shops from containing Greed or Super Greed. This is useful if you intend to visit shops later for any reason.
•  Broken Padlock allows you to open locked doors by bombing them instead of spending a key. However, it also has an extra effect of allowing you to bomb open the door to the Mausoleum, which normally requires you to take damage to open. This is mainly useful if you intend to go to the Mausoleum as Tainted Eden.

With the amount of power you’re now packing, Tainted Cain should be strong enough to beat any challenge in the game. Here are some tips on how to get the most bang for your buck. If you play your cards right and get a little lucky, you may even be able to clear all of Tainted Cain’s marks except Greed Mode in a single run!

The  R Key is critical to this. R Key is an Active Item that, when used, sends you back to Basement I while keeping all the items (and completion marks) you already obtained. Because Tainted Cain can craft as many R Keys as he wants, it means he can potentially cycle through the game indefinitely as long as you’re able to make a new R Key before the end of each cycle. There are a few caveats to keep in mind, however.

The timer does not reset when using the R Key; as you’ve probably been playing for at least an hour by now, this means Tainted Cain cannot access Boss Rush or Hush. The following items can help with that:

•  Mama Mega is a one-time-use Active Item that can blow open the door to Boss Rush or Hush as long as you use it on the appropriate floor (Depths II or Mausoleum II for Boss Rush, Womb II for Hush). Since it’s an Active Item, however, it competes for space with your R Keys or any other items you were hoping to bring with you.
•  Strange Key is a Trinket unlocked by clearing Sheol, the Cathedral, the Dark Room, and the Chest as Tainted Eve. As long as you have it in your inventory, the door to Hush (but not Boss Rush) will be open regardless of how much time has passed. Note that the key’s other purpose, giving you items when used in tandem with Pandora’s Box, will remove the Strange Key from your inventory, so avoid Pandora’s Box if you intend to fight Hush this way.

These will allow you to bypass the timer restrictions and clear Boss Rush and Hush no matter how long it takes. Carrying one Mama Mega and one Strange Key is much preferable to carrying two Mama Megas, so consider unlocking the Strange Key as Tainted Eve when you get the chance. That way, you can use your second Active Item slot to carry the R Key.

Note that you can also face Boss Rush on the Antibirth path, before the Corpse. If you don’t have the Strange Key and want to keep an open slot for an R Key, you can clear Boss Rush on your Antibirth cycle and Hush on a different cycle, with one Mama Mega crafted for each.

When you defeat The Beast at the end of the Ascent, the game will automatically end, with no opportunity to use an R Key. As such, The Beast should be the final cycle you complete.

Unfortunately, Mega Satan has a similar problem; when you defeat Mega Satan, the game has a 50% chance of ending immediately, with no opportunity to R Key; the other 50% is opening a portal to the Void, in which case you are free to use your R Key (or go to the Void and fight Delirium first, if desired). Either way, Mega Satan should be the second-to-last completion mark you aim for, with the understanding that you may not be able to continue after.

Of course, reaching Mega Satan is a conundrum in itself; you require two Key Pieces, which can only be obtained from defeating the Angels in Angel Rooms. Thankfully, Key Pieces do not burst when Tainted Cain tries to pick them up.

 Eucharist (Unlocked by clearing the Void as Magdalene) and  The Stairway (Unlocked by clearing the Cathedral as Jacob & Esau) can be used to force Angel Rooms to appear at the end or beginning of floors, respectively. You probably do not need these to get enough Angel Rooms to appear, but it certainly does not hurt.

 Dad’s Key is an Active Item that can be used to force any door to open, including Mega Satan’s door. If you don’t want to fight the Angels, or if you smelted Filigree Feather against my advice, this is an alternative method to accessing Mega Satan. This is less preferable to simply assembling the real key, however, since it takes up an Active Item slot.

Knowing what we know now, it is time to figure out what order both minimizes the number of cycles we need to complete, and runs the least risk of prematurely ending the game. I propose the following:

1. Hush, Cathedral, and the Chest. If you’re lucky enough to get a portal to the Void after defeating ??? (20% chance), take it.
2. Antibirth path.
3. Sheol, Dark Room, and Mega Satan. If you didn’t get the Void previously, pray you get it after Mega Satan (50% chance).
4. Ascent.

Boss Rush can be done on any of these runs, provided you make a Mama Mega.

If you really don’t want to risk missing out on the Void and Delirium, you can alternatively go directly to the Void after defeating Hush, but then you’ll have to make five total cycles instead of four, and you still may wind up ending the game after Mega Satan.

This is the real holy grail of Binding of Isaac exploitation. So exploitative, in fact, that I’d only recommend doing this if you really don’t care about earnestly challenging yourself and just want to cheat your way to victory.

 Clicker is an Active Item that, when used, changes your current character to a different one, allowing you to set up a game-breaking run as Tainted Cain and then switch to a different character to win the run as them.

Be warned; at the time of writing, there are some serious glitches with the Clicker that can ruin your run, potentially:

• Turning into Tainted Forgotten will potentially softlock the game; you will become the immobile pile of bones, with no Soul around to move or pick you up. You can still use the Clicker to become somebody else, but that requires having either a second charge saved up or extra batteries within bone-swinging distance.
• Turning into Tainted Isaac will immediately crash the game. Unfortunately, there is no way around this.

With these two bugs in mind, we can draw three conclusions: First, always be surrounded by a large number of batteries when using the Clicker, in case you become Tainted Forgotten (in Greed Mode, standing on a battery that’s for sale in the shop will suffice). Second, before you use the Clicker, exit the game back to the main menu, and then select Continue. This will create a “save point” from which the game can reload if it crashes due to Tainted Isaac. This will at least prevent you from losing all your game-breaking progress if you do crash. Third, because Tainted Forgotten and Tainted Isaac are broken, we will not be able to use Tainted Cain to complete runs as them; you’ll have to beat them the old-fashioned way.

Unfortunately, Tainted Isaac is the endpoint of any Clicker; the order you turn into characters seems to be pre-seeded, and re-loading the game after a crash and using the Clicker again will give you the same characters in the same order; if Tainted Isaac is the first character you turn into… tough luck. You may want to consider crafting the Clicker early in a breaking run, before you start crafting tons of items, and “testing” it by using it until it crashes the game. Then when you reload the game, you’ll know which characters are available to you and how soon Tainted Isaac ruins things.

NOTE: I am currently testing how this works, and I think I may have found a workaround that re-shuffles the Clicker’s character order; on one breaking run, I crafted the Clicker, and found that it gave me Tainted Forgotten -> Tainted Forgotten -> Tainted Bethany -> Tainted Isaac/game crash. Content to do a run as Tainted Bethany, I reloaded my game and proceeded as normal with crafting powerful items, but when I finally finished and crafted the Clicker again, I wound up turning into Tainted Lost instead of Tainted Forgotten. I do not know for certain what caused the Clicker’s seed to re-shuffle, but it may honestly be as simple as destroying the first Clicker and crafting a second one.

One thing to note is that using the Clicker as Tainted characters will only turn you into other Tainted characters, and using the Clicker to turn into regular characters will only turn you into regular characters. As such, Tainted Cain cannot become regular characters using the Clicker. However, there is a workaround; extra lives that revive you as a different character will allow you to become a regular character when you die and revive, from which you can then use the Clicker to become any other regular character. The items that allow this are Lazarus’ Rags, Judas’ Shadow, Ankh, and the Missing Poster Trinket. Note that due to how extra lives work, any extra lives from Dead Cat will be consumed before the aforementioned items’ extra life, so sadly you cannot bring Dead Cat lives with you when becoming one of the regular characters.

Another note about the Clicker itself is that every time you use it, the most recent item you’ve collected will be removed, as a toll of sorts; because you (probably) have the Car Battery, however, two items will be removed. The last thing you want is to lose all those powerful items you crafted, so before you start using the Clicker, I recommend crafting a bunch of junk items you don’t mind losing; scooping up 8 Lil’ Batteries from your battery room will let you craft as many Rotten Babies as you like, which can give you a good buffer of items to “spend” on Clicker uses.

One last note on the Clicker; Tainted Eden’s items get shuffled every time they take damage; this has a strong chance of ruining your powerful item set, or worse, giving you an item set that just crashes the game outright. The door to the Mausoleum normally requires you take damage to open it, so if you’re intending to clear the Antibirth path as Tainted Eden, you’ll want to bring an alternative way of opening that door, such as Dad’s Key or that Broken Padlock I mentioned earlier.

Now that you’ve used the Clicker to hopefully become an interesting character, you can proceed through the rest of the game as that character, and secure an easy victory. Note that since you need one Active Item slot for the Clicker, you only have one other slot for either a Mama Mega or an R Key. As such, you’ll have to choose whether you want to go to Boss Rush or clear two runs back-to-back, unless you’re lucky enough to find a Mama Mega or R Key naturally during the run.

This is slightly less exploitative than using the Clicker.

 Eden’s Blessing is a craftable item unlocked by defeating Hush as Eden. It has a relatively minor effect of slightly boosting your Tears stat, but its real potential is hidden; the next time you start a new run (R Key does not count), you will begin with a random item.

A nifty bonus on its own, but Tainted Cain can exploit this; by crafting additional Eden’s Blessings, you can start your next run with more items; ten is the limit.

Craft ten Eden’s Blessings as Tainted Cain, and then finish your run (either as Tainted Cain or as somebody else; it doesn’t matter. You can even die if you want, so long as the run is officially over). The next time you start a run as any character, you’ll begin with ten items right off the bat. Which items you get is totally random, but you could potentially get something that easily lets you win even as a difficult character.

One of the handiest uses for Tainted Cain is making items not for winning runs, but just for filling out your Collection page on the main menu; after all, obtaining every item is necessary for 100% completion. Some items such as Mega Blast, Delirious!, and Pyromaniac are just plain rarer than other items, so this is a good way to collect them for completion.

Note that not every item can be crafted; rather than talk about how to craft every single item in the game, I’ll instead talk about which items cannot be crafted by Tainted Cain. Note that several of these can also be obtained using Chaos, Spindown Dice, or Death Certificate. Also remember that Tainted Cain himself cannot pick up any of these except for the story-related items, though he can potentially find them and then use Clicker to become somebody else capable of picking them up.

• Story-related items: The Polaroid, The Negative, Key Pieces, Knife Pieces, Broken Shovel Pieces and Mom’s Shovel, Dad’s Note, and Dogma. Just playing the story should let you encounter these items naturally.
• Items specific to Tainted characters: Flip, Sumptorium, Hold, and the Bag of Crafting itself. Just play as Tainted characters to add these items to your collection.
• Recall. This item is exclusive to Tainted Forgotten when he has Birthright. Using the Clicker to become Tainted Forgotten while you have Birthright should suffice, softlock though it may be.
• Specific payouts from machines: A Dollar (from Slot Machines), Crystal Ball (from Fortune Teller Machines), Blood Bag and IV Bag (from Blood Donation Machines), and Skatole (from Shell Games). These can only be obtained by playing their respective machine until it pays out with the desired item.
• Tammy’s Head. As of Repentance, this item can only naturally be found as a prize from the Crane Game, or in gold treasure rooms in Greed Mode.
• Redemption. Sacrifice Rooms and Confessionals may pay out with this item if you’ve previously taken a Devil Deal.
• Head of the Keeper. The only way to find this is as a very rare drop chance when blowing up shopkeepers.
• The Small Rock. This is occasionally found when blowing up tinted rocks.
• Wait What? has a chance of replacing Butter Bean on any given run.
• Drops related to the Horsemen: Cube of Meat, Ball of Bandages, A Pony, and White Pony. Tainted Cain cannot craft these, but he can craft a Book of Revelations if for some reason you’re having trouble encountering the Horsemen. Just remember you’ll need to become somebody else before picking up the items.
• Steven. For some reason, this item cannot be crafted, only obtained from defeating the Steven boss 20% of the time.
• A Lump of Coal and Head of Krampus. These can only be obtained as drops from defeating Krampus.
• Broken Glass Cannon. Craft the regular Glass Cannon and then take damage while holding it.
• C Section. The only way to get this item is via Death Certificate or Spindown Dice. Remember that while Tainted Cain can craft Death Certificate and Spindown Dice, he cannot actually pick the item up himself.

Some achievements from Afterbirth+’s booster packs are not related to defeating big bosses, but instead require you to find certain combinations of items within a single run. Due to the random nature of the game, it can be difficult and frustrating to actually get lucky enough to find these items. Thankfully, Tainted Cain comes to the rescue.

Unlocking this achievement requires you grow in size five times within a single run. The easiest way is by finding a XI – Strength Card and duplicating it with the D1, then using it five times.

Unlocking this achievement requires you bring Pandora’s Box all the way to the Dark Room and use it there. This one isn’t too difficult to accomplish without Tainted Cain, but if you’re having trouble getting lucky with a run that both includes Pandora’s Box and is strong enough to reach the Dark Room, you can always use Tainted Cain to easily clear it. Note that repeatedly using a Sacrifice Room after the 12th use has a chance of just teleporting you directly to the Dark Room, if you don’t care about the rest of the run.

Unlocking this achievement requires you obtain two Technology items in a single run. Potential candidates include Technology, Technology 2, Tech X, Tech.5, Robo-Baby, and Robo-Baby 2.0.

Unlocking this achievement requires you to boost your tears stat ten times in a single run. Simply crafting ten of an item such as the Torn Photo will work, or eating ten Tears Up Pills if you happen to find one and can duplicate it with the D1.

Unlocking this achievement requires you pick up the Rubber Cement item five times, not necessarily in a single run. If you’re having trouble finding it in your runs, or just tend to avoid it due to disliking the item, you can craft it as many times as needed as Tainted Cain.

Unlocking this achievement requires you use five Gulp! Pills in a single run, and is pretty difficult. Even if you break the game to amass infinite pills as Tainted Cain, there’s no guarantee that Gulp! will be in the rotation that run. All you can do is keep trying. Remember that each run has 13 different Pill types available from the pool of 50. Also remember that Gulp! Pills themselves must be unlocked first by completing a Victory Lap.

Unlocking this achievement requires you to stack the homing tears effect on yourself twice at the same time; once from a passive item such as Spoon Bender or Godhead, and a second time from using either a I – The Magician Card or Telepathy For Dummies. I recommend Spoon Bender and Telepathy For Dummies.

Unlocking this achievement requires you obtain any three celestial items in a single run:

• Any of the eleven Planetarium items.
• Any of the twelve Zodiac-themed items.
• Zodiac (the item itself)
• Magic 8 Ball
• Crystal Ball
• Deck of Cards
• Tarot Cloth
• Echo Chamber
• Card Reading
• Star of Bethlehem

I personally recommend crafting Magic 8 Ball, Scorpio, and Aquarius, as they have relatively simple and cheap crafting recipes.

All in all, Tainted Cain really is a broken character, and I’m sure future updates to the game will restrict his capabilities by removing certain items from the crafting pool. Until then, he’s a useful tool for clearing certain achievements you just can’t seem to manage on your own. That being said, I wouldn’t recommend relying on Tainted Cain for everything; if you don’t bother to ever play as the really challenging characters legitimately, are you really getting your money’s worth out of this game? After all, the whole point of this game is to be challenging, and at times frustrating, but worth it for the satisfaction of pulling off an amazing win or struggling against insurmountable odds. I myself try to avoid using Tainted Cain to earn completion marks as other characters aside from a few times, but I figure I may as well document it for those who are curious.