Eternal God - Roadmap for 100% completion

Although you might feel tempted to start on Hardmode right away, I strongly recommend avoiding it at first. Hardmode in The Binding of Isaac is brutal and often unfair, and most new players won’t survive long enough to make real progress.

There are no in-game unlockables tied to Hardmode, only achievements. These will be covered later in section Chapter 4: Hardmode, Memento Mori.

If you started with Rebirth or any of its expansions, keep in mind that many items shared between the games behave differently in the original The Binding of Isaac. Effects, stats, and synergies are often changed. For example, Cat-O-Nine-Tails no longer provides a damage up in the original version.

Keep an eye on these unlocks during your runs.

• Mom’s Bottle Of Pills - Use the Blood Donation Machine 20 times over multiple runs
  
• Mom’s Contacts - Obtain both Mom’s Eye and either Mom’s Underwear, Heels, Lipstick, Bra, Pad, Bottle of Pills, Knife Purse or Coin Purse
  
• Mr. Mega! - Destroy 30 tinted rocks over multiple runs
  
• Small Rock - Destroy 50 rocks over multiple runs
  
• The Bandage - Defeat 4 Harbinger bosses in one run: Famine (Basement/Cellar), Pestilence (Caves/Catacombs), War (Depths/Necropolis), Death or Conquest (Womb/Utero), and the Headless Horseman (any floor). Using The Book of Revelations forces the floor boss to be a Harbinger, but if you already fought one on the first part of a floor, it won’t appear again on the second.
  
• The Bean - Destroy 50 poops over multiple runs
  
• The Book of Sin - Defeat all of the Seven Deadly Sins minibosses over multiple runs: Envy, Gluttony, Greed, Lust, Pride, Sloth, Wrath
  
• The Common Cold - Obtain 2 of the following items in one run: Roid Rage, The Virus or Growth Hormones
  
• The Gamekid - Enter 10 different arcades over multiple runs
  
• The Halo -Defeat either Mom or Mom’s Heart with the Bible
  
• The Necronomicon - Use four XIII Death cards over multiple runs
  
• The Parasite - Obtain 2 of the following items in one run: Bob’s Rotten Head, Dead Cat, Max’s Head or Tammy’s Head
  
• The Shears - Die 100 times

Your first priority is to unlock the Womb, Sheol, Cathedral, and the Chest, while also unlocking all characters and several miscellaneous items from the previous section.

• Magdalene - Have 7 red heart containers at once
  
• Cain - Have 55 pennies at once (spent pennies do not count)
  
• Judas - Defeat Mom's Heart
  
• Eve - Make 2 Devil Deals in one run
  
• ??? - Defeat It Lives!
  
• Samson - Skip 2 Treasure Rooms and defeat Mom

The Womb / Utero floors unlock after defeating Mom in Depths II for the first time. From that point on each time you defeat Mom’s Heart you earn a total of 10 unlockables:

• #1 Judas (Character)
  
• #2 The Noose
  
• #3 The Nail
  
• #4 The Quarter
  
• #5 The Fetus
  
• #6 Everything is Terrible!!! (More Champion enemies spawn)
  
• #7 The Wafer
  
• #8 Money = Power
  
• #9 It Lives! (Boss, replaces Mom's Heart)
  
• #10 ??? (Character)

The Sheol becomes permanently unlocked after defeating It Lives!. Until then, it can only be accessed by:

• Inside a Devil or Angel room after beating Mom’s Heart,
  
• Using a Joker card,
  
• Using We Need to Go Deeper inside a Devil or Angel room,
  
• Teleporting to the Error Room from Womb / Utero II.

The Dark Room does not exist in the original Isaac the way it does in Rebirth or its expansions. The Cathedral becomes permanently unlocked after defeating It Lives!. Confusingly enough, it cannot be entered through an Angel Room, like in Rebirth or its expansions. The Chest is only accessible by interacting with the chest after defeating Isaac in the Cathedral while holding The Polaroid trinket.

• The Polaroid - Defeat Isaac 6 times

After unlocking The Polaroid, it will drop in future runs after defeating Mom. You must hold it all the way through the Cathedral. Once you enter The Chest, you are free to drop it.
The Chest is a brutal floor, especially when compared to Rebirth and its expansions.

There are a total of 10 challenges to complete. Completing a challenge will unlock an item or consumable. The following challenges unlock good rewards that should be unlocked as soon as possible:

• 1. Dark was the Night - The Candle
  
• 3. Large Marge - Burnt Penny
  
• 4. 9 Deaths - Guppy's Tail
  
• 6. The Doctor's Revenge! - Epic Fetus
  
• 7. Meat 4 Evar! - SMB Super Fan!
  
• 8. Spider Boy! - Spider Butt (especially useful later on in Hardmode)
  
• 9. Isaac Was Good Today - Counterfeit Penny
  
• 10. The Purist - Daddy's Love

Some of the later challenges won't be unlocked until a bit further in the game, keep an eye on which challenges you unlock. To achieve Eternal God it is necessary to complete all challenges eventually.

At this point, you should start consistently completing runs using different paths. Keep in mind that there are achievements for clearing the Basement, Caves, Depths, and Womb without taking damage — alternate floor types like the Cellar also count.

To achieve Eternal God and unlock every achievement, you must beat Sheol, the Cathedral, and the Chest with every character. I will note per character to prioritise the Sheol or Cathedral and Chest path first.

Defeat Mom's Heart/ It Lives! as ??? to unlock the D6 as a starting item for Isaac Go to Sheol first

• Mom's Knife - Defeat Satan as Isaac

Go to Sheol first

• Guardian Angel - Defeat Satan as Magdalene

Then go to the Cathedral and Chest

• Maggy's Faith - Defeat ??? as Magdalene

Go to the Cathedral and Chest first

• Cain's Eye - Defeat ??? as Cain

Then go to the Sheol

• Sack of Pennies - Defeat Mom's Heart/ It Lives! as Cain
  
• Bomb Bag - Defeat Satan as Cain

Go to the Cathedral and Chest first

• Curved Horn - Defeat Isaac as Judas
  
• Judas' Tongue - Defeat ??? as Judas

Go to the Cathedral and Chest First

• Sacrificial Dagger - Defeat Isaac as Eve
  
• Eve's Bird Foot - Defeat ??? as Eve

Then go to the Sheol

• Demon Baby - Defeat Satan as Eve

Go to the Sheol first

• Forget Me Now - Defeat Satan as ???

Go to the Cathedral and Chest First

• Bloody Penny - Defeat Isaac as Samson
  
• Samson's Lock - Defeat ??? as Samson

After these unlocks, you can either finish unlocking the remaining character-, miscellaneous-, and challenge-related items and achievements, or dive into Hardmode. I recommend getting as many unlockables as possible and becoming familiar with the game before jumping into Hardmode.

The name does not lie.

Hardmode is not for the faint of heart. Although there are no in-game unlockables tied to this mode, there are 14 achievements.

• 1 each for beating Mom, It Lives!, Satan, Isaac, ???, and getting any ending.
  
• 7 achievements for completing the game on Hardmode with each character.
  
• 1 for beating the game as every character, and finally the elusive Eternal God for unlocking everything and fully completing Hardmode.

This means you don’t have to complete every path with every character.

I recommend choosing the Cathedral / Chest route only once for the achievement, and then finishing your remaining runs by beating Satan instead. This lets you skip a stage (The Chest), and frees your trinket slot so you don’t have to carry The Polaroid if you don’t want to.

• More Champion enemies spawn.
  
• Bosses no longer drop red hearts on defeat.
  
• Curses appear more often.
  
• Alternate (harder) floors appear more frequently.
  
• Troll Bombs disguise themselves as normal bombs and transform on contact.
  
• Damage ups soft-cap at 5 damage (reduced scaling afterward).
  
• Brimstone, Epic Fetus, and Dr. Fetus spawn less often.
  
• Enemies drop items less frequently.
  
• Room-clear rewards appear less often.
  
• Guppy’s Paw converts 2 soul hearts → 1 red container instead of 3.
  
• XIX – The Sun heals 7 red hearts instead of fully healing.
  
• Full Health pills heal 5 red hearts instead of full.
  
• Max HP increases from 12 → 16 hearts.
  
• The D6 can make items disappear instead of rerolling.
  
• It Lives! has 45% more health.
  
• Eternal Challenge Rooms replace normal Challenge Rooms.

If you unlocked every item and achievement before conquering Hardmode, you will have already achieved Eternal God status. If not, the remaining unlockables and achievements should be a cakewalk compared to the trials of Hardmode.

If you still have not found all items you can cross reference your Collection tab with a site like Platinum God.[tboi.com]

Your work is still not done — Repentance awaits.

And just like that, it was over.