History ScrappyWeapon / TheBindingOfIsaac

* Monstro's Lung, which makes Isaac's tears shoot up and fall down in an arc, greatly reducing range, but also having him spew many tears at once. The issue? Tears are significantly reduced, to less than half your original speed. This ends up dooming Isaac if he meets any fast enemies, enemies that stay away from Isaac, or enemies that are both. What makes it worse is that it's in many item pools, allowing it to end a good run if you get it in a late floor.

** And it does not end there. Not only is this item unwieldy, and the air strikes take ''ages'' to come down, but it is by far one of the most boring and monotonous items in the game in terms of its interactions with other items, if it even ''can'' interact with any items that you pick up during a run with Epic Fetus. All of the few synergies that it does have are rather mediocre. While it does synergize with bomb effects, most other items in the game are overridden by Epic Fetus, and it just deletes any powerful synergies that the player does have after picking it up.
** Not only that, but why does this item even ''exist'' in the '''SECRET ROOM ITEM POOL''' of all places?! You could have gotten a powerful GameBreaker item in a Secret Room, such as Echo Chamber, Rock Bottom, or even the coveted R Key... but nope! Instead of any of that, you got this trash item. Just imagine how many players have been disappointed to find this in a Secret Room. Also, why should it even be considered a quality 4 item when it is not that good to begin with?

* '''[[BoltOfDivineRetribution Trisagion]]''' looks a lot like the equivalent to a "holy Brimstone" shot, but in reality has a lot to live up to. The light blasts you shoot pierce enemies but are horrendously weak, dealing 1/3 of your current damage per tick, and much like Technology, cause no knockback. With a high Shot Speed (a stat liked for its ability to reach enemies faster), it also becomes even weaker, as the blast of light will go through the enemy while dealing only scratch damage. Only with a low Shot Speed (which is pretty much ViolationOfCommonSense) does it become stronger, as the damage per tick is more constant, but even so, the items that reduce the Shot Speed (like Lost Contact, Godhead, or Sacred Heart) are so rare, and there are many more alternatives available, it's often not worth picking it up. And on top of that, it has a massive tendency to make the game lag like crazy. It's no surprise why the item gets the EmbarrassingNickname of "Tri-BAD-ion" by some players.

* '''[[BoltOfDivineRetribution Trisagion]]''' looks a lot like the equivalent to a "holy Brimstone" shot, but in reality has a lot to live up to. The light blasts you shoot pierce enemies but are horrendously weak, dealing 1/3 of your current damage per tick, and much like Technology, cause no knockback. With a high Shot Speed (a stat liked for its ability to reach enemies faster), it also becomes even weaker, as the blast of light will go through the enemy while dealing only scratch damage. Only with a low Shot Speed (which is pretty much ViolationOfCommonSense) does it become stronger, as the damage per tick is more constant, but even so, the items that reduce the Shot Speed (like Lost Contact, Godhead, or Sacred Heart) are so rare, and there are many more alternatives available, it's often not worth picking it up. It's no surprise why the item gets the EmbarrassingNickname of "Tri-BAD-ion" by some players.

** Not only that, but why does this item even ''exist'' in the '''SECRET ROOM ITEM POOL''' of all places?! You could get a powerful GameBreaker item in a Secret Room, such as Echo Chamber, Rock Bottom, or even the coveted R Key... but nope! You get a trash item that is hard to control. Just imagine how many players have been disappointed to find this in a Secret Room. Also, why should it even be considered a quality 4 item when it is not that good to begin with?

** And it does not end there. Not only is this item unwieldy and the air strikes take ''ages'' to come down, but it is by far one of the most monotonous items in the game. All of the few synergies that it does have are rather mediocre. While it does synergize with bomb effects, most other items in the game are overridden by Epic Fetus, and it just deletes any powerful synergies that the player does have.

* '''[[RandomEffectSpell 3 Dollar Bill, Fruit Cake, and Playdough Cookie]]''' have also won quite the amount of detractors as well because of their tendency to proc explosive effects that one wouldn't like to find — all three can roll Fire Mind, while Fruit Cake can also roll Ipecac. It is possible for a run to [[GameOver end]] by picking up Fruit Cake and having it roll Ipecac at the worst possible time. Therefore, it is the worst item in this category.

* '''[[RandomEffectSpell 3 Dollar Bill, Fruit Cake, and Playdough Cookie]]''' have also won quite the amount of detractors as well because of their tendency to proc explosive effects that one wouldn't like to find — all three can roll Fire Mind, while Fruit Cake can also roll Ipecac.

* '''[[ThrowDownTheBomblet Bob's Brain]]''' and '''[[ActionBomb BBF]]'''. The former is an explosive projectile familiar that you can fire at enemies for [[StatusAilment poison damage]]. The latter is a friendly Boom Fly that bounces across the room, exploding on contact with an enemy. What makes them divisive is that they have a tendency to respawn as you're firing your tears in close-quarters; there's nothing worse than having them respawn and explode on top of an adjacent enemy, catching you in the blast. Sometimes, BBF can even damage you ''as soon as you enter a room!'' Bob's Brain, at least, [[AuthorsSavingThrow was toned down a bit]] in ''Afterbirth'', as it now can't be fired for a few seconds after it spawns or after you enter a room, preventing surprise explosions.

* '''[[PlayingWithFire Fire Mind]]''' allows you to shoot tears that inflict [[StatusAilment burn damage over time]] to enemies… but each tear has a chance to explode on contact with an enemy, with said explosion having a generous blast radius — not unlike that of Ipecac — but dealing pitiful damage to enemies. It completely ruins your primary attack's use for close-quarters combat, only allowing for hit-and-run combat. And even then, there are some enemies like Globins that [[NoSenseOfPersonalSpace love to be in your face]], making avoiding damage during hit-and-run tactics ''very'' hard. The worst part? The chance for explosions [[ScrappyMechanic scales with your Luck stat]], so the more luck you have, the more explosions you create. At least the resulting explosion deals less damage to you than that of a regular bomb, and ''Repentance'' made the explosion size smaller. Picking up certain tear modifiers, however, eliminates the explosion but leaves the fire damage, like [[BreathWeapon Brimstone]], [[KnifeNut Mom's Knife]], or [[RayGun Technology]]. It is also a non-issue for Tainted Lilith in ''Repentance'', since her tears are fired from a distance via Gello.

* '''[[ThrowDownTheBomblet Bob's Brain]]''' and '''[[ActionBomb BBF]]'''. The former is an explosive projectile familiar that you can fire at enemies for [[StatusAilment poison damage]]. The latter is a friendly Boom Fly that bounces across the room, exploding on contact with an enemy. What makes them divisive is that they have a tendency to respawn as you're firing your tears on close-quarters; there's nothing worse than having them respawn and explode on top of an adjacent enemy, catching you in the blast. Sometimes, BBF can even damage you ''as soon as you enter a room!'' Bob's Brain, at least, [[AuthorsSavingThrow was toned down a bit]] in ''Afterbirth'', as it now can't be fired for a few seconds after it spawns or after you enter a room, preventing surprise explosions.

* '''[[HorsemenOfTheApocalypse 7 Seals]]''' has its issue where its randomness and the effects of each of the little Harbingers can make it somewhat unreliable, but one of the item's main problems is the War transformation. The locusts[[note]]which are colored flies with different effects depending on the current harbinger[[/note]] he spawns (red locusts) are highly damaging, but can be easily turned into you due to the fact they have the same blast radius and damage as a bomb. Simply put, much like BBF, the red locusts can damage you whenever you enter a room whether you want it or not, making it a prime reason why this item is looked down on. And if the game is feeling {{spiteful|AI}}, War may be the most common Harbinger 7 Seals will roll, causing red locusts to spawn over and over. Of course, everything that applies to this item also applies to the '''[[ActionBomb Locust of War]]''' trinket. Thankfully, ''Repentance'' [[AuthorsSavingThrow made the blast radius of red locusts much smaller]], and while this does make them less effective at crowd control, it's a small price to pay when it means they're no longer blowing up in your face all the time.
* '''IBS''', similar to Tainted ???'s gameplay gimmick, has a chance to give you one of several throwable poops or otherwise poop-themed effects whenever you damage an enemy. ''Unlike'' Tainted ???, you can't control when to use these poops — they're automatically deployed as soon as the effect activates. This is bad enough on its own, since you're forced to stop firing when you're holding a poop, but it can also give you an ''active'' throwable bomb or the effects of an Explosive Diarrhea pill at complete random. Even green poops, ordinarily one of the more useful kinds due to the poison clouds they emit, can be a liability. If the RNG decides to give you fire poop while you're standing near them (or one of their gas clouds)... boom!

** ...that is, unless you're playing Tainted Jacob, as from the same update onward, picking Birthright up will cause Dark Esau to [[FromBadToWorse spawn another clone of himself that will also charge at you]]. Despite the significant buffs Tainted Jacob received in the same update, if you thought juggling an angry soul trying to kill you was enough, now try juggling ''two''! On the other hand, if you decide to face the risks and play to the item's strengths, both souls charging at you can make facing hordes of enemies or certain bosses easier, since [[ThereIsNoKillLikeOverkill their huge contact damage is essentially]] ''[[ThereIsNoKillLikeOverkill doubled]]''.

* '''[[PlayingWithFire Fire Mind]]''' allows you to shoot tears that inflict [[StatusAilment burn damage over time]] to enemies... but each tear has a chance to explode on contact with an enemy, with said explosion having a generous blast radius — not unlike that of Ipecac — but dealing pitiful damage to enemies. It completely ruins your primary attack's use on close-quarters combat, only allowing for hit-and-run combat. And even then, there are some enemies like Globins that [[NoSenseOfPersonalSpace love to be in your face]], making avoiding damage during hit-and-run tactics ''very'' hard. The worst part? The chance for explosions [[ScrappyMechanic scales with your Luck stat]], so the more luck you have, the more explosions you create. At least the resulting explosion deals less damage to you than that of a regular one, and ''Repentance'' made the explosion size smaller. Picking up certain tear modifiers, however, eliminates the explosion but leaves the fire damage, like [[BreathWeapon Brimstone]], [[KnifeNut Mom's Knife]] or [[RayGun Technology]]. It is also a non-issue for Tainted Lilith in ''Repentance'', since her tears are fired from a distance via Gello.
* '''[[RandomEffectSpell 3 Dollar Bill, Fruit Cake, and Playdough Cookie]]''' have also won quite the amount of detractors as well because of their tendency to proc explosive effects that one wouldn't like to find - all three can roll Fire Mind, while Fruit Cake can also roll Ipecac.

* '''IBS''', similar to Tainted ???'s gameplay gimmick, has a chance to give you one of several throwable poops or otherwise poop-themed effects whenever you damage an enemy. ''Unlike'' Tainted ???, you can't control when to use these poops--they're automatically deployed as soon as the effect activates. This is bad enough on its own, since you're forced to stop firing when you're holding a poop, but it can also give you an ''active'' throwable bomb or the effects of an Explosive Diarrhea pill at complete random. Even green poops, ordinarily one of the more useful kinds due to the poison clouds they emit, can be a liability. If the RNG decides to give you fire poop while you're standing near them (or one of their gas clouds)... boom!

* '''[[PowerGivesYouWings The Bible]]''' is a 6-room charge activated item that grants flight and... that's it. Having flight is a big advantage, as it increases overall mobility and allows for obtaining pickups that you would otherwise have no access to. But having an item that grants such effect each 6 rooms, when there's already a bevy of items that do it permanently? Sounds lackluster. On the other hand, the item [[OneHitKill instantly kills]] Mom and Mom's Heart[=/=]It Lives, but be careful not to use it on Satan (or in ''Wrath of the Lamb'' only, Isaac or Blue Baby), as it'll [[PressXToDie kill]] ''[[PressXToDie you]]'' instead. ''Repentance'' made it a bit less situational by buffing its charge time from 6 to 4 rooms.

* On the other side of the spectrum is '''[[KnifeNut Mom's Knife]]''', one of the biggest {{Game Breaker}}s but also considered by a few people to be one of the dullest items in the game. The knife you can throw is extremely powerful at its longest range, dealing enough damage to do a number on even {{Final Boss}}es, especially if they're stationary (like Mega Satan). As a result, some players (including seasoned veterans) often opt to skip this item, in an attempt to make [[NintendoHard the difficulty of the game]] truly shine. Even those that will take Mom's Knife can find the item unwieldy at times, such as trying to fire diagonally but instead doing so horizontally[=/=]vertically due to the input being frame perfect. ''Repentance'' worked around this issue by making the input no longer require to be frame perfect.
* '''[[BeamSpam Technology 2]]''' is another very infamous example. Having a constant laser that fires while you do is a nice idea for an item, but the main problem is that it halves down your firing rate and, on top of it, cuts down your damage stat ''directly'' as well, and significantly so. The laser itself, much like Technology, has no knockback, which when combined with the massive damage reduction and the reduced rate of fire means you'll need to shoot down the enemy with the laser AND the tear to make the damage count. ''Rebirth'' further emphasized its problems by making the laser itself deal even less damage, causing tanky enemies to [[DeathOfAThousandCuts take AGES to go down]] unless you happen to have good Damage. Finally, when used by Cain (or alongside items that make you fire tears only from the right eye, like Lead Pencil from ''Afterbirth†''), tears won't fire at all anymore, only firing the laser that deals pitiful damage. As a result, compared to the more traditional [[RayGun Technology]], Tech 2 is widely considered to be a huge downgrade. Additionally, ''Rebirth'' introduced Tech.5, a laser that has a random rate of fire but doesn't replace your main source of fire nor affect your stats, and even has its own effects, which pretty much pushed Technology 2 '''''further''''' down the hill. Fortunately, ''Repentance'' [[RescuedFromTheScrappyHeap removed it from this category]] by making it no longer reduce your Damage stat, making the rate of fire downgrade much lower, granting the beam slight knockback (much like with other ''Tech'' items), and granting the regular Technology effect when used by Cain[=/=]with items that fire from the right eye, meaning that it's now much more worth a try.

* '''Isaac's Heart''' is also ''very much'' this '''in spades'''. Your body no longer has a hurtbox, which sounds great... if it wasn't for the fact said hurtbox will now be following your back as a familiar. One that enemies will be 100% of the time aiming for. Knowing how the mechanics for familiars work (and as later infamously seen with characters like Lilith's Incubus), having a hitbox that trails behind you is not a good thing at all. It's especially terrible when it's not the first familiar on your line, as it makes the heart much harder to properly protect. It's because of these traits that players will almost always avoid it like the plague. Keyword being "almost" because, in spite of its negatives, the item does have a few situational positives that can lead to some {{Game Break|er}}ing combos that make infinite use of [[CastFromHitPoints red heart containers]], such as Blood Donation Machines or the IV Bag for [[EleventyZillion infinite money]], offering to to Demon Beggars until they pay out with an item, using the [[StatusBuff Razor Blade]] for infinite damage stacking, or using [[SmartBomb Blood Rights]] to damage everything in the room until it's empty of enemies. The heart familiar can also fortunately be sacrificed with the [[DealWithTheDevil Sacrificial Altar]] in ''Afterbirth†'' for a free item in return. Still, without a way to exploit Isaac's Heart to your benefit, do '''''not''''' ever think about touching that item pedestal containing the item.

* Whereas many of the "Bean" items are purposely bad, but accepted due to balance purposes, the same can't be said about the '''[[JokeItem Butter Bean]]'''. It's an active item that only has the effect of producing a small fart that can knock back some enemies. At least it recharges spontaneously, and in ''Afterbirth'' it can deflect bullets. ''Afterbirth†'' sort of removed it from this category, as swapping it with another item repeatedly can transform it into "Wait What?", an identical-looking bean that loses the fast recharge time in exchange for creating a circle of rock waves around Isaac. ''Repentance'' also made knockback from the farts (from both items) deal damage to enemies if they collide with obstacles, walls or other enemies. Still, considering that all this item does is a miserable fart, you'll still want to swap Butter Bean with another MUCH better active item or transform it into "Wait What?", both as soon as possible.

* The '''[[ExactlyWhatItSaysOnTheTin Glass Cannon]]''', on release, used to reduce your health to half a red heart, but gave you an on-command massive tear with scaling (but always high) damage. However, following the November 4th, 2015 update, it instead reduced you to half a heart — including soul hearts and black hearts — turning you into, appropriately enough... a GlassCannon. To say that people are not amused is a massive understatement. However, it becomes one of the most useful items in the hands of The Lost, who has no health. ''Repentance'' took it from this category for some after it was made so that it no longer depletes your health to half a heart, instead only significantly increasing damage taken in that room and temporarily causing it to break if you're hit while carrying it; while still very risky, it's a massive improvement over its original effect.

* '''[[BladeOnAStick Spear of Destiny]]''' was seemingly introduced as the Angel Room equivalent to Mom's Knife in the Devil Room (both items working like swords), but in practice it's extremely lackluster. Both items deal twice your damage on contact, but Mom's Knife deals damage up to 20 times per second, whereas the Spear of Destiny hits... only 3 times per second. While the hitbox for the spear is bigger, the fact that Mom's Knife deals damage drastically faster makes it a much safer choice at the end of the day. A few active items that grant invincibility, such as Unicorn Stump or The Gamekid, can work around the issue and make for a usable way to deal melee damage, but again, the fact Mom's Knife can do the very same does not help its case. As of ''Repentance'', the existence of an actual sword item in [[InfinityPlusOneSword Spirit]] [[CoolSword Sword]] only makes Spear of Destiny even more redundant.
* '''[[WaveMotionGun Mega Blast]]''' sits in a similar boat to Mom's Knife in that it's an overpowered item that is disliked for being overpowered, except it takes the concept of "overpowered" [[PurposelyOverpowered up to eleven]]. Not only is Mega Blast a cheap item in the Devil Room (at a cost of only one heart container, compared to other {{Game Breaker}}s like Brimstone or Mom's Knife which cost two containers), the gigantic laser you shoot lasts for 15 seconds, enough time to vanquish even {{Damage Sponge|Boss}} {{Final Boss}}es like Hush, Mother or even ''Delirium''. The unlock requirements are why it is Purposely Overpowered to begin with (defeating Mega Satan as all and every character), but the fact this item alone makes every room in the game and every boss in the game a complete joke is what removes much of its charm for many. And again, like Mom's Knife, Mega Blast had a flaw pre-''Repentance'' that made it unwieldy for many people, in while its charge time of ''12 rooms'' before it can be used again counterbalances its strength, it also requires 3 batteries to fully charge instead of one (unlike its Angel Room counterpart [[SummonBiggerFish Delirious]]), heavily cutting on its usability; ''Repentance'' made this issue less prominent by reducing the number of batteries to 2.
* ''Afterbirth'' added a bunch of new transformations, but '''Conjoined''' is... dubiously useful. After picking up three shooting familiars, Isaac grows two faces on his cheeks that fire tears along side him. Great! Unfortunately, it also comes with a sizable damage down. The faces also fire diagonally like The Wiz, making them basically worthless for actually hitting anything. If you have a bunch of familiars, odds are your stats aren't very good to begin with, and Conjoined is just the gut punch to a bad run. ''Repentance'' also arguably made this even worse, since it added tonnes of new familiars into the Conjoined pool, making the transformation much more likely to get.

* '''[[OneHitKill Plan C]]'''. It kills every enemy and boss in the game in a single hit... followed by [[PressXToDie killing you]] [[YouAreAlreadyDead 3 seconds later]]. It's basically a SmartBomb with barely any of the "smart" factor in it, as it absolutely requires you to have an extra life in order to make the most use out of it. Its extreme damage output is also offset by bosses with multiple phases to their fights, meaning bosses like Hush or Mega Satan will not survive the first hit but will be ready for Round 2 while you simply [[YetAnotherStupidDeath die]]; thus, using the item in their second phase is the next best thing. Furthermore, using it on Delirium will cause you to die first because of its death animation taking so long to finish. It doesn't help that, while it's only likely to appear 1 time out of 5 in an item pool, it can be found in a total of ''5 item pools'' in the game, making it surprisingly more common than one would imagine.

* The '''[[TheGambler Crooked Penny]]''' is another 4-room charge that essentially works like a multiple-use Diplopia... but has a catch. The item's description, "50/50", is ExactlyWhatItSaysOnTheTin: it either duplicates items (even those that need to be bought) 50% of the time, or it fails to do so 50% of the time and instead removes every collectible in the room and spawns a measly penny. Half of the time you'll be happy and with your hands full, while the other half you'll be empty handed and cursing the RandomNumberGod for not allowing you to duplicate a GameBreaker like Brimstone. And knowing the game's AI tendency to [[SpitefulAI troll the player into oblivion]]... yeah. Overall, this amounts to one of the most divisive items in the entire game.

* '''[[BoltOfDivineRetribution Trisagion]]''' looks a lot like the equivalent to a "holy Brimstone" shot, but in reality has a lot to live up to. The light blasts you shoot pierce enemies but are horrendously weak, dealing 1/3 of your current damage per tick, and much like Technology, cause no knockback. With a high Shot Speed (a stat liked for its ability to reach enemies faster), it also becomes even weaker, as the blast of light will go through the enemy while dealing only scratch damage. Only with a low Shot Speed (which is pretty much ViolationOfCommonSense) does it become stronger, as the damage per tick is more constant, but even so, the items that reduce the Shot Speed (like Lost Contact, Godhead or Sacred Heart) are so rare, and there are many more alternatives available, it's often not worth picking it up. It's no surprise why the item gets the EmbarrassingNickname of "Tri-BAD-ion" by some players.
** ''Repentance'' only added salt to the wound, as the expansion introduced a much more direct "holy" equivalent of Brimstone in the form of Revelation, which suffers from roughly none of the aforementioned issues and adds flight on top of that. The expansion ''did'' buff Trisagion by giving the blasts slight knockback, and introduced a slew of synergies to go with it (though it does resulting the game easily crashing)... including a "Scrappy Synergy" with Ipecac where the Ipecac-powered Trisagion blasts start exploding immediately after you fire them, resulting in you taking unavoidable self-damage whenever you fire (and eventually finding yourself [[GameOver seeing Isaac's last will]]). Thankfully, the November 2021 update buffed Trisagion again by causing on-proc effects to only happen on collision, removing the combo from this category and now being [[GameBreaker one of the most powerful]] [[DifficultButAwesome (if still risky)]] [[GameBreaker comboss you can get]].

* Planetariums have been received well due to the slew of items with good to excellent effects (such as [[SuperSpeed Mercurius]], [[DishingOutDirt Terra]], [[AnIcePerson Uranus]] and [[ChargedAttack Neptunus]]), but a few of them have a lackluster reputation.

** When you think of '''Jupiter''', the first thing you'll think of is the [[Myth/ClassicalMythology Roman god of Thunder]] and the gas giant of a planet in the Solar System... but not of a "gas giant" in [[ToiletHumor the literal sense]]. Jupiter is a sizeable speed downgrade that forces you to stay still to build speed and, as soon as you walk, release it in a burst of {{fart|illery}}s. Not only is its effect mediocre at best, it forces you to play the game differently without offering much reward in return and, to boot, [[ArsonMurderAndJaywalking you're gonna have to hear the sounds of farts constantly and the item comes with]] [[{{Gonk}} one of the ugliest costumes in the game]]. Its only upside is that the item does become more useful by picking up speed upgrades. Otherwise, compared to most several of the new Planetarium items (even Venus and Mars), Jupiter has quickly managed to get on people's nerves.

* '''TMTRAINER''' invokes the concept of GameBreakingBug to a degree never ever seen before. Picking it up seemingly does nothing... until you find an item. The items you will find in the run are completely glitched, and become [[RandomEffectSpell random combinations of 2-3 item effects, alongside randomly activating based on certain events (room clearing, killing an enemy, taking damage), and either being active or passive items]]. You may probably guess where the item is going, and yes, it is perfectly and completely capable of activating any undesirable effect, including from the ones in this page, from self-damage by using the item, to summoning Damocles' sword ready to kill you from the first screw-up, to outright [[YetAnotherStupidDeath dying ala Plan C]] after killing an enemy. This item also stars in a hidden challenge that is essential for getting OneHundredPercentCompletion, meaning you'll at least get a taste of just how chaotic it can be. [[SarcasmMode Have fun!]]
** Originally, plot-relevant items[[note]]The Polaroid, The Negative, the Key Pieces, the Knife Pieces and Dad's Note[[/note]] were also affected by TMTRAINER, meaning your run was practically guaranteed to end early if you ever pick TMTRAINER up -- this resulted in a [[UnintentionallyUnwinnable softlock]] in the pre-ascent version of Mausoleum/Gehenna, as there was no way to progress without picking up Dad's Note... which was glitched and unusable. [[WordOfGod Edmund later clarified this was]] [[GameBreakingBug a bug]], and to the relief of one too many, it was fixed as of the November 2021 update, meaning these items are now fortunately safe from the effects of TMTRAINER.

* '''[[Franchise/{{Pokemon}} Missing]] [[RandomNumberGod No.]]''' is this '''in spades'''. Picking it up causes it to reroll your items like the D4 and modify your stats, but the worst part is that, whether you want it or not, this will happen ''again'' at the start of each floor. This can turn any build you may have (be it a decent one or even a GameBreaker build) prior to picking Missing No. up, into a LuckBasedMission on which you'll hope the items granted to you don't make you underpowered or even worse, cause the run to be (borderline) unplayable. The item is also one of the few unable to get rerolled by an actual reroll effect like the D4, D100, 1-pip[=/=]6-pip dice rooms, so you'll have to deal with holdiong on to the item. On the other hand, it is also able to turn any bad run you may have into a Game-Breaker build, but it is not something you should be relying on in the first place. Unlike many other items in the page, ''Repentance'' only made the item ''even worse'' due to the nerfs made to reroll effects, as while any items that are removed can be encountered again during the run, any transformations from items that grant them and and any red heart containers you had from health upgrades will now be removed if you lose the items that granted them.

** ''Repentance did'' buff Trisagion by giving the blasts slight knockback, and introduced a slew of synergies to go with it (though it does resulting the game very easily crashing)… including a "Scrappy Synergy" with Ipecac that dethrones all and everything in this page. While on their own both are usable, if you pick them up together and don't have explosion immunity, you'll quickly find yourself [[GameOver seeing Isaac's last will]]. The reason for this is that the Ipecac-powered Trisagion blasts start exploding immediately after you fire them, resulting in you taking unavoidable self-damage whenever you fire. As the final nail in Trisagion's coffin, the same DLC introduced a much more direct "holy" equivalent of Brimstone in the form of Revelation, which suffers from roughly none of the aforementioned issues and adds flight on top of that.

* Planetariums have been received well due to the slew of items with good to excellent effects ([[SuperSpeed Mercury]], [[DishingOutDirt Terra]], [[AnIcePerson Uranus]] and [[ChargedAttack Neptunus]] especially), but a few of them have a lackluster reputation.

* '''TMTRAINER''' invokes the concept of GameBreakingBug to a degree never ever seen before. Picking it up seemingly does nothing... until you find an item. The items you will find in the run are completely glitched, and become [[RandomEffectSpell random combinations of 2-3 item effects, alongside randomly activating based on certain events (room clearing, killing an enemy, taking damage), and either being active or passive items]]. You may probably guess where the item is going, and yes, it is perfectly and completely capable of activating any undesirable effect, including from the ones in this page, from self-damage by using the item, to summoning Damocles' sword ready to kill you from the first screw-up, to outright [[YetAnotherStupidDeath dying ala Plan C]] after killing an enemy. Plot-relevant items like the Polaroids and key pieces are also affected by TMTRAINER, meaning your run is almost guaranteed to end early if you ever pick it up--this results in a [[UnintentionallyUnwinnable softlock]] in the pre-ascent version of Mausoleum/Gehenna, as there's no way to progress without picking up Dad's Note... which is now glitched and unusable. TMTRAINER also stars in a hidden challenge that is essential for getting OneHundredPercentCompletion, meaning you'll at least get a taste of just how chaotic it can be. [[SarcasmMode Have fun!]]
* The '''Birthright''' is a shop item that provides a unique effect tailored to the character you're playing as. While some can be underwhelming, most of these effects are incredibly useful, typically patching up a key weakness or improving on the character's strengths. The problem is that [[ObviousBeta only about half of the characters in the game have an effect implemented]], and while the item can still spawn for the others, picking it up does nothing. This means for players who don't know the effects, it's a complete toss-up as to whether it'll be a godsend or a waste of 15 coins, while to those who do, it still feels like a waste of a trip to the shop when it shows up for a character it doesn't work on.

* '''TMTRAINER''' invokes the concept of GameBreakingBug to a degree never ever seen before. Picking it up seemingly does nothing... until you find an item. The items you will find in the run are completely glitched, and become [[RandomEffectSpell random combinations of 2-3 item effects, alongside randomly activating based on certain events (room clearing, killing an enemy, taking damage), and either being active or passive items]]. You may probably guess where the item is going, and yes, it is perfectly and completely capable of activating any undesirable effect, including from the ones in this page, from self-damage by using the item, to summoning Damocles' sword ready to kill you from the first screw-up, to outright [[YetAnotherStupidDeath dying ala Plan C]] after killing an enemy. This item also stars in a hidden challenge that is essential for getting OneHundredPercentCompletion, meaning you'll at least get a taste of just how chaotic it can be. [[SarcasmMode Have fun!]]

** ''Repentance did'' buff Trisagion by giving the blasts slight knockback, and introduced a slew of synergies to go with it (though it does resulting the game very easily crashing)… including a "Scrappy Synergy" with Ipecac that dethrones all and everything in this page. While on their own both are usable, if you pick them up together and don't have explosion immunity, you'll quickly find yourself [[GameOver seeing Isaac's last will]]. The reason for this is that the Ipecac-powered Trisagion blasts start exploding immediately after you fire them, resulting in you taking unavoidable self-damage whenever you fire.

Generally speaking, most passive items that cause [[StuffBlowingUp explosions]] that you can't control are looked down upon the community, due to the fact that their blast radius can easily damage you. As such, picking up Host Hat or Pyromaniac to NoSell the explosions from these items is recommended:

* The '''Birthright''' is a shop item that provides a unique effect tailored to the character you're playing as. While some can be underwhelming, most of these effects are incredibly useful, typically patching up a key weakness or improving on the character's strengths. The problem is that [[ObviousBeta only about half of the characters in the game have an effect implemented]], and while the item can still spawn for the others, picking it up does nothing. This means for players who don't know the effects, it's a complete toss-up as to whether it'll be a godsend or a waste of 15 coins, while to those who do, it still feels like a waste of a trip to the shop.

* '''[[RandomEffectSpell 3 Dollar Bill and Fruit Cake]]''' have also won quite the amount of detractors as well because of their tendency to proc explosive effects that one wouldn't like to find - both can roll Fire Mind, while Fruit Cake can also roll Ipecac.

** ''Repentance did'' buff Trisagion by giving the blasts slight knockback, and introduced a slew of synergies to go with it... including a "Scrappy Synergy" with Ipecac that dethrones all and everything in this page. While on their own both are usable, if you pick them up together and don't have explosion immunity, you'll quickly find yourself [[GameOver seeing Isaac's last will]]. The reason for this is that the Ipecac-powered Trisagion blasts start exploding immediately after you fire them, resulting in you taking unavoidable self-damage whenever you fire.

* '''[[SmartBomb The Necronomicon]]''' isn't disliked so much as it is just ignored due to there being many more alternatives available. It's a 6-room charge item that deals 40 damage to every single enemy in the room, meaning it can kill tender enemies and heavily soften the tankier ones, so it's essentially a Death tarot card on command and can save a lot of time in dealing with hordes of enemies, especially early-game. Similarly to The Bible, however, its 6-room charge is what makes it pretty underwhelming for some. Even a cheaper alternative from ''Rebirth'' is Blank Card + Death, which takes 4 rooms to charge. Much like The Bible, ''Repentance'' buffed The Necronomicon by reducing its charge time from 6 to 4 rooms.

* '''[[Franchise/{{Pokemon}} Missing]] [[RandomNumberGod No.]]''' is this '''IN SPADES'''. Picking it up causes it to reroll your items like the D4 and modify your stats, but the worst part is that, whether you want it or not, this will happen ''again'' at the start of each floor. This can turn any build you may have (be it a decent one or even a GameBreaker build) prior to picking Missing No. up, into a LuckBasedMission on which you'll hope the items granted to you don't make you underpowered or even worse, cause the run to be (borderline) unplayable. The item is also one of the few unable to get rerolled by an actual reroll effect like the D4, D100, 1-pip[=/=]6-pip dice rooms, so you'll have to deal with holdiong on to the item. On the other hand, it is also able to turn any bad run you may have into a Game-Breaker build, but it is not something you should be relying on in the first place. Unlike many other items in the page, ''Repentance'' only made the item ''even worse'' due to the nerfs made to reroll effects, as while any items that are removed can be encountered again during the run, any transformations from items that grant them and and any red heart containers you had from health upgrades will now be removed if you lose the items that granted them.

* The '''[[JokeItem Dataminer]]''' {{invoke|d Trope}}s this without much fanfare, due to being an item put in the game as merely [[TakeThatAudience a jab at the]] {{Content Leak}}ers that infamously datamined ''Rebirth''. It's a 4-room charge item that merely flips enemy sprites and grants random tear effects, while increasing one of Isaac's stats and decreasing another. Not only are its effects horrendous, they are also reliant on the RandomNumberGod and fighting enemies becomes wonky. Oh, and [[ArsonMurderAndJaywalking it distorts the level's music, too]].

* '''[[BoltOfDivineRetribution Trisagion]]''' looks a lot like the equivalent to a "holy Brimstone" shot, but in reality has a lot to live up to. The light blasts you shoot pierce enemies but are fairly weak, dealing 1/3 of your current damage per tick, and much like Technology, cause no knockback. With a high Shot Speed (a stat liked for its ability to reach enemies faster), it also becomes even weaker, as the blast of light will go through the enemy while dealing only scratch damage. Only with a low Shot Speed (which is pretty much ViolationOfCommonSense) does it become stronger, as the damage per tick is more constant, but even so, the items that reduce the Shot Speed (like Lost Contact, Godhead or Sacred Heart) are so rare, and there are many more alternatives available, it's often not worth picking it up. It's no surprise why the item gets the EmbarrassingNickname of "Tri-BAD-ion" by some players.

** '''[[DashAttack Mars]]''' is also not bad,but it certainly feels unwieldy at times. Its effect is certainly excellent: by pressing a movement button twice, it grants you a dash attack that makes you invincible for its duration and deals great damage by itself; it makes Curse Rooms free of entry and also stacks with other items that deal contact damage (like the newly buffed Aries) while synergizing with others (like Kamikaze! and A Pony[=/=]White Pony). However, the way it activates has caused a problem too many by activating it when one doesn't want to, which when combined with nearby sources of damage can lead to accidental self-damage and, in the worst of cases, [[YetAnotherStupidDeath an accidental death]] through little fault of your own. This becomes a bigger problem if your computer starts to lag, as the activation window for Mars becomes much wider due to the slowdown.

* '''[[PlayingWithFire Fire Mind]]''' allows you to shoot tears that inflict [[StatusAilment burn damage over time]] to enemies... but each tear has a chance to explode on contact with an enemy, with said explosion having a generous blast radius — not unlike that of Ipecac — but dealing pitiful damage to enemies. It completely ruins your primary attack's use on close-quarters combat, only allowing for hit-and-run combat. And even then, there are some enemies like Globins that love to be in your face, making avoiding damage during hit-and-run tactics ''very'' hard. The worst part? The chance for explosions [[ScrappyMechanic scales with your Luck stat]], so the more luck you have, the more explosions you create. At least the resulting explosion deals less damage to you than that of a regular one, and ''Repentance'' made the explosion size smaller. Picking up certain tear modifiers, however, eliminates the explosion but leaves the fire damage, like [[BreathWeapon Brimstone]], [[KnifeNut Mom's Knife]] or [[RayGun Technology]]. It is also a non-issue for Tainted Lilith in ''Repentance'', since her tears are fired from a distance via Gello.

* '''[[HolyBurnsEvil Holy Water]]''' is a familiar that activates when taking damage, but compared to other similar familiars, it breaks and merely spawns a small puddle of blue creep that deals some damage to enemies, similarly to the Lemon Mishap effect. Since enemies are still able to move around when they stand on the creep, the damage they'll take is scratch damage at best, especially during later chapters where enemies are tankier and faster (and from the Womb onward, you take a full heart of damage each time). Did we mention it can also be used only once per room? This makes not only for a widely disliked item, but also for one of the go-to examples when arguing about why the Devil Room item pool is better than the Angel Room item pool, even with the existence of other powerful items like [[InfinityPlusOneSword Sacred Heart or Godhead]]. ''Repentance'' fortunately threw Holy Water a bone and [[AuthorsSavingThrow heavily reworked it]], making it a Bob's Brain-esque familiar that not only can be used more than once per room, but makes the creep petrify enemies and bosses on contact with the puddle, causing them to take the full brunt of the damage, which firmly removed it from this category.

* '''Tiny Planet''' from ''Rebirth'' is another particularly infamous one. Sure, it's a stat upgrade and has some interesting synergies, but the orbiting tears on their own cover much less range in front of you than firing them straight and are nigh-impossible to aim, meaning that players tend to avoid it like the plague. It doesn't help that the effect combines badly with certain strong items, such as Dr. Fetus and, before ''Repentance'', Mom's Knife. Only a few items gain a net positive with this one, including Brimstone and Technology.
* The '''[[JokeItem Butter Bean]]''', introduced in ''Rebirth''. It's an active item that only has the effect of producing a small fart that can knock back some enemies. At least it recharges spontaneously, and in ''Afterbirth'' it can deflect bullets. ''Afterbirth†'' sort of removed it from this category, as swapping it with another item repeatedly can transform it into "Wait What?", an identical-looking bean that loses the fast recharge time in exchange for creating a circle of rock waves around Isaac. ''Repentance'' also made knockback from the farts (from both items) deal damage to enemies if they collide with obstacles, walls or other enemies. Still, considering that all this item does is a miserable fart, you'll still want to swap Butter Bean with another MUCH better active item or transform it into "Wait What?", both as soon as possible.

* '''[[BladeOnAStick Spear of Destiny]]''' was seemingly introduced as the Angel Room equivalent to Mom's Knife in the Devil Room, but in practice it's extremely lackluster. Both items deal twice your damage on contact, but Mom's Knife deals damage up to 20 times per second, whereas the Spear of Destiny hits... only 3 times per second. While the hitbox for the spear is bigger, the fact that Mom's Knife deals damage drastically faster makes it a much safer choice at the end of the day. Alongside a few other items like Holy Water (pre-''Repentance''), Breath of Life and Trisagion, this item is another of the go-to examples when arguing about why the Devil Room item pool far eclipses the Angel Room item pool. As of ''Repentance'', the existence of an actual sword item in [[InfinityPlusOneSword Spirit]] [[CoolSword Sword]] only makes Spear of Destiny even more redundant.

** '''[[DashAttack Mars]]''' isn't bad as it is unwieldy at times. Its effect is certainly excellent: by pressing a movement button twice, it grants you a dash attack that makes you invincible for its duration and deals great damage by itself; it makes Curse Rooms free of entry and also stacks with other items that deal contact damage (like the newly buffed Aries) while synergizing with others (like Kamikaze! and A Pony[=/=]White Pony). However, the way it activates has caused a problem too many by activating it when one doesn't want to, which when combined with nearby sources of damage can lead to accidental self-damage and, in the worst of cases, [[YetAnotherStupidDeath an accidental death]] through little fault of your own. This becomes a bigger problem if your computer starts to lag, as the activation window for Mars becomes much wider due to the slowdown.
** When you think of '''Jupiter''', the first thing you'll think of is the [[Myth/ClassicalMythology Roman god of Thunder]] and the gas giant of a planet in the Solar System... but not of a "gas giant" in [[ToiletHumor the literal sense]]. Jupiter is a sizeable speed downgrade that forces you to stay still to build speed and, as soon as you walk, release it in a burst of {{fart|illery}}s. Not only is its effect mediocre at best, it forces you to play the game differently without offering much reward in return and, to boot, [[ArsonMurderAndJaywalking you're gonna have to hear the sounds of farts constantly and the item comes with]] [[{{Gonk}} one of the ugliest costumes in the game]]. Its only upside is that the item does become more useful by picking up speed upgrades. Otherwise, compared to most several of the new Planetarium items (even Mars), Jupiter has quickly managed to get on people's nerves.
** '''Venus''' gives Isaac a red heart container and an aura that charms nearby enemies... and that's it. The aura has a very small radius, making it mostly restricted to melee enemies. It's also barely an upgrade over [=2Spooky=], a 1-heart Devil deal that gives Isaac a fear aura. It's certainly not ''bad'', but it really stings to give up several item rooms only to get a fairly minor benefit out of it. It's nowhere near impactful enough to warrant being a Planetarium item.
* '''TMTRAINER''' invokes GameBreakingBug to a degree never ever seen before. Picking it up seemingly does nothing... until you find an item. The items you will find in the run are completely glitched, and become [[RandomEffectSpell random combinations of 2-3 item effects, alongside randomly activating based on certain events (room clearing, killing an enemy, taking damage), and either being active or passive items]]. You may probably guess where the item is going, and yes, it is perfectly and completely capable of activating any undesirable effect, including from the ones in this page, from self-damage by using the item, to summoning Damocles' sword ready to kill you from the first screw-up, to outright [[YetAnotherStupidDeath dying ala Plan C]] after killing an enemy.

* '''[[RandomEffectSpell 3 Dollar Bill, Fruit Cake and Playdough Cookie]]''' have also won quite the amount of detractors as well (moreso the former two) because of their tendency to proc explosive effects that one wouldn't like to find - all three can roll Fire Mind, while Fruit Cake can also roll Ipecac.

* '''My Reflection''' is a particularly infamous one, as it just makes your tears boomerang around wildly, cutting your range and making it hard to aim. Some combinations using it will screw you even harder, such as combining it with Ipecac or Bob's Rotten Head, causing your explosive projectiles to [[HoistByHisOwnPetard boomerang right back at you]]. Even worse is that the Suicide King challenge in ''Rebirth'' sticks you with the My Reflection + Ipecac combo [[StopHittingYourself for the entire run]]. It works surprisingly well with Azazel, however, as it's one of the few items that increases his otherwise short range.

* The '''[[JokeItem Dataminer]]''' {{invoke|d Trope}}s this without much fanfare, due to being an item put in the game as merely [[TakeThatAudience a jab at the]] {{Content Leak}}ers that infamously datamined ''Rebirth''. It's a 4-room charge item that merely flips enemy sprites and grants random tear effects, while increasing one of Isaac's stats while decreasing the other. Not only are its effects horrendous, they are also reliant on the RandomNumberGod and fighting enemies becomes wonky. Oh, and [[ArsonMurderAndJaywalking it distorts the level's music, too]].

* Planetariums have been received well due to the slew of items with good to excellent effects ([[SuperSpeed Mercury]], [[DishingOutDirt Terra]], [[AnIcePerson Uranus]] and [[ChargedAttack Neptunus]] especially), but two certain ones have already received a lackluster reputation: Mars and Jupiter.

* '''[[SmartBomb The Necronomicon]]''' isn't disliked so much as it is just ignored due to there being many more alternatives available. It's a 6-room charge item that deals 40 damage to every single enemy in the room, meaning it can kill tender enemies and heavily soften the tankier ones, so it's essentially a Death tarot card on command and can save a lot of time in dealing with hordes of enemies, especially early-game. Similarly to The Bible, however, its 6-room charge what makes it pretty underwhelming for some. Even a cheaper alternative from ''Rebirth'' is Blank Card + Death, which takes 4 rooms to charge. Much like The Bible, ''Repentance'' buffed The Necronomicon by reducing its charge time from 6 to 4 rooms.

* '''[[OneHitKill Plan C]]'''. It kills every enemy and boss in the game in a single hit... followed by [[PressXToDie killing you]] [[YouAreAlreadyDead 3 seconds later]]. It's basically a SmartBomb with barely any of the "smart" factor in it, as it absolutely requires you to have an extra life in order to make the most use out of it. Its extreme damage output is also offset by bosses with multiple phases to their fights, meaning bosses like Hush or Mega Satan will not survive the first hit but will be ready for Round 2 while you simply [[YetAnotherStupidDeath die]]; thus, using the item in their second phase is the next best thing. Furthermore, using it on Delirium will cause you to die first because of its death animation taking so long to finish. It doesn't help that, while its only likely to appear 1 time out of 5 in an item pool, it can be found in a total of ''5 item pools'' in the game, making it surprisingly more common than one would imagine.

* '''[[SmartBomb The Necronomicon]]''' isn't disliked so much as it is just ignored due to there being many more alternatives available. It's a 6-room charge item that deals 40 damage to every single enemy in the room, meaning it can kill tender enemies and heavily soften the tankier ones, so it's essentially a Death tarot card on command and can save a lot of time in dealing with hordes of enemies, especially early-game. Similarly to The Bible, however, it's its 6-room charge what makes it pretty underwhelming for some. Even a cheaper alternative from ''Rebirth'' is Blank Card + Death, which takes 4 rooms to charge. Much like The Bible, ''Repentance'' buffed The Necronomicon by reducing its charge time from 6 to 4 rooms.

* '''[[HolyBurnsEvil Holy Water]]''' is a familiar that activates when taking damage, but compared to other similar familiars, it breaks and merely spawns a small puddle of blue creep that deals some damage to enemies, similarly to the Lemon Mishap effect. Since enemies are still able to move around when they stand on the creep, the damage they'll take is scratch damage at best, especially during later chapters where enemies are tankier and faster (and from the Womb onward, you take a full heart of damage each time). Did we mention it can also be used only once per room? This makes not only for a widely disliked item, but also for one of the go-to examples when arguing about why the Devil Room item pool is better than the Angel Room item pool, even with the existence of other powerful items like [[InfinityPlusOneSword Sacred Heart or Godhead]]. ''Repentance'' fortunately threw Holy Water a bone and [[AuthorsSavingThrow heavily reworked it]], making it a Bob's Brain-esque familiar that not only can be used more than once per room, but makes the creep petrify enemies and bosses on contact with the creep, causing them to take the full brunt of the damage, which firmly removed it from this category.

* '''[[DeathOfAThousandCuts Soy Milk]]''', which is in roughly the same boat as Tiny Planet. At the cost of slashing 80% of your damage and tear size, it ''massively'' boosts the firing rate of your tears, to the point that a starting Isaac with Soy Milk has enough of a fire rate to shoot 30 tears per second. Unfortunately, the game has a hardcoded limit of ''15'' tears per second, meaning that while it's technically a bit more [=DPS=] than your default tears, that's only if you make ''every shot count''. Given the tears knockback', the game's enemies and their erratic movement patterns, making all your tiny tears hit their mark so the damage output is at least decent is a huge pain in the neck — the [=DPS=] is so poor, all bosses become {{Marathon Boss}}es, and even ''[[TheGoomba flies]]'' take a lot more shots before they're down. And to add insult to injury, it's a special item in ''Rebirth'', so once you see it, your chances of a ''really'' good item in your current run fall dramatically! Only once you gain a '''lot''' of Damage ups or synergize Soy Milk with other certain items does it become a GameBreaker, due to its high firing rate carrying over. Fortunately, in ''Afterbirth'', Soy Milk is no longer a special item, meaning that it no longer interferes with your ability to get really good items just by showing up. As of ''Repentance'', the tears' knockback was also reduced dramatically (allowing tears to hit their target more frequently), the tear cap is no longer hardcoded at 15 per second, items that increase rate of fire ''affect'' Soy Milk's fire rate (which combines well with the previous change), a good number of items gained ''synergies'' with it, and there's finally the possibility of getting [[GameBreaker Rock Bottom]] alongside it, which prevents the damage reduction while keeping the increased rate of fire.

* The '''[[ExactlyWhatItSaysOnTheTin Glass Cannon]]''', on release, used to reduce your health to half a red heart, but gave you an on-command massive tear with scaling (but always high) damage. However, as of the November 4th, 2015 update, it now reduces you to half a heart — including soul hearts and black hearts — turning you into, appropriately enough... a GlassCannon. To say that people are not amused is a massive understatement. However, it becomes one of the most useful items in the hands of The Lost, who has no health. ''Repentance'' took it from this category for some after it was made so that it no longer depletes your health to half a heart, instead only significantly increasing damage taken after use in that room and causing it to break; while still very risky, it's a massive improvement over its original effect.

* '''[[BladeOnAStick Spear of Destiny]]''' was seemingly introduced as the Angel Room equivalent to Mom's Knife in the Devil Room, but in practice it's extremely lackluster. Both items deal twice your damage on contact; however, the knife you wield with Mom's Knife deals damage up to 20 times per second, whereas the spear you wield when using Spear of Destiny deals... only 3 times per second. The hitbox for the spear is bigger yes, but the fact that Mom's Knife deals damage drastically faster makes it a much safer choice at the end of the day. Alongside a few other items like Holy Water (pre-''Repentance''), Breath of Life and Trisagion, this item is another of the go-to examples when arguing about why the Devil Room item pool far eclipses the Angel Room item pool. As of ''Repentance'', the existence of an actual sword item in [[InfinityPlusOneSword Spirit]] [[CoolSword Sword]] only makes Spear of Destiny even more redundant.

* '''Glyph of Balance''' has a neat concept on paper, but fails to consistently make use of it because of issues regarding its design. The item modifies the pickups dropped by [[EliteMook champion enemies]] to provide you with whatever pickup the game deems you need (more on its complicated criteria can be read on [[https://bindingofisaacrebirth.fandom.com/wiki/Glyph_of_Balance the other wiki]]). The problem lies on how it triggers, which is by killing champion enemies. On Normal mode, champions are guaranteed to drop a pickup, but they are rare compared to regular enemies. However, on Hard mode, Champions are more common but only have a 1/3 chance to drop anything at all. This oxymoron causes the item to become surprisingly situational and, in some cases, completely useless, since you'll rarely be receiving drops from champions either way. ''Repentance'', however, brought a major buff to the item by making it now modify ''room drops'', which are common occurance compared to champion drops, and as a result the item has become significantly more appetizing and a catalyst in soul heart generation, especially in a game where such strategies got nerfed to the ground.
* '''[[OneHitPolykill Plan C]]'''. It kills every enemy and boss in the game in a single hit... followed by [[PressXToDie killing you]] [[YouAreAlreadyDead 3 seconds later]]. It's basically a Smart Bomb with barely any of the "smart" factor in it, as it absolutely requires you to have an extra life in order to make the most use out of it. Its extreme damage output is also offset by bosses with multiple phases to their fights, meaning bosses like Hush or Mega Satan will not survive the first hit but will be ready for Round 2 while you simply [[YetAnotherStupidDeath die]]; thus, using the item in their second phase is the next best thing. Furthermore, using it on Delirium will cause you to die first because of its death animation taking AGES to play. It doesn't help that, while its only likely to appear 1 time out of 5 in an item pool, it can be found in a total of ''5 item pools'' in the game, making it surprisingly more common than one would imagine.

* The '''[[TheGambler Crooked Penny]]''' is another 4-room charge that essentially works like a multiple-use Diplopia... but has a catch. The item's descrpition, "50/50", is ExactlyWhatItSaysOnTheTin: it either duplicates items (even those that need to be bought) 50% of the time, or it fails to do so 50% of the time and instead spawns a measly penny. Half of the time you'll be happy and with your hands full, while the other half you'll be empty handed and cursing the RandomNumberGod for not allowing you to duplicate a GameBreaker like Brimstone. And knowing the game's AI tendency to [[SpitefulAI troll the player into oblivion]]... yeah. Overall, this amounts to one of the most divisive items in the entire game.

* '''Lacryphagy''' is rather divisive as well. Tears will quickly decelerate and become capable of absorbing other tears, causing them to grow until they burst into tears. While the main tear also deals the combined damage of each tear that fed it, the burst tears also deal half damage. What's more, not only must you pay attention to the enemies in the current room, but you are also forced to pay attention to how large the tear has become before it bursts. The item also has a tendency to not synergize with other tear modifiers as well. It's likely because of this that ''Repentance'' gave the item's synergy potential a massive buff, as items like Brimstone or Technology now synergize with it.