Achievements

Achievements are an optional mechanic added in Fiend Folio: Reheated that are obtained by completing challenges, gaining completion marks as certain characters, or meeting some other requirements, similarly to achievements in vanilla The Binding of Isaac. Some content like collectibles, trinkets, pickups and a tainted character will be locked behind these achievements, and need to be completed in order to encounter and use in runs.

Upon first starting up a run once Fiend Folio: Reheated is installed, a notification will pop up on screen, which will ask the player to choose between having unlocks be enabled or disabled: When enabled, these achievements can be obtained, and their respective content cannot be encountered until those achievements are completed; When disabled, content will not be locked behind achievements and completion marks, and can all be encountered normally in runs.

The player can go into the "Dead Sea Scrolls" menu (by pressing C or F1 on keyboard by default) and go to Fiend Folio > Unlocks > Unlocks Manager page and change this option at any time. They may also be able to change specific achievements to be locked/unlocked through the menu, without having to complete the required goal. In addition, the Fiend Folio > Unlocks > Achievements page can be used to see all the player's achievements, and will include hints for how to obtain each one.

There are currently 83 total unlocks in Fiend Folio: Reheated, with 36 needing to be unlocked through character completion marks, 10 needing to be unlocked from the MOD's challenges, and the other 37 being achievements that are unlocked through meeting certain requirements.

This page is about Achievements added in Fiend Folio. More information about Achievements in general can be found in the vanilla page.

All Achievements

Character Completion Marks

Fiend

Icon	Name	Unlock Method
	Immoral Hearts	Defeat Mom as Fiend
	Lil Fiend	Defeat Mom's Heart or It Lives on Hard Mode as Fiend
	Imp Soda	Defeat Isaac as Fiend
	Heart of China	Defeat ??? as Fiend
	Fiend Mix	Defeat Satan as Fiend
	Prank Cookie	Defeat The Lamb as Fiend
	Pyromancy	Defeat Mega Satan as Fiend
	GMO Corn	Defeat Boss Rush as Fiend
	+3 Fireballs	Defeat Hush as Fiend
	Fiend's Horn	Defeat Delirium as Fiend
	The Devil's Harvest	Defeat Mother as Fiend
	Fetal Fiend	Defeat The Beast as Fiend
	Cool Sunglasses	Defeat Ultra Greed as Fiend
	Jack Cards	Defeat Ultra Greedier as Fiend
	The Fiend Folio	Get every Hard Mode completion mark as Fiend
	The Bastard	Use Red Key to open the hidden closet in Home as Fiend

Golem

Icon	Name	Unlock Method
	Pet Rock	Defeat Mom's Heart or It Lives on Hard Mode as Golem
	Golem's Rock	Defeat Isaac as Golem
	Golem's Orb	Defeat ??? as Golem
	Cherry Bomb	Defeat Satan as Golem
	Bridge Bombs	Defeat The Lamb as Golem
	Massive Amethyst	Defeat Mega Satan as Golem
	Solemn Vow	Defeat Boss Rush as Golem
	Dice Goblin	Defeat Hush as Golem
	Perfectly Generic Object	Defeat Delirium as Golem
	Eternal D12	Defeat Mother as Golem
	Astropulvis	Defeat The Beast as Golem
	Molten Penny	Defeat Ultra Greed as Golem
	Nyx	Defeat Ultra Greedier as Golem
	Snow Globe	Get every Hard Mode completion mark as Golem

The Bastard

Icon	Name	Unlock Method
	Chunk of Tar	Defeat Isaac, ???, Satan, The Lamb as The Bastard
	+3 Fireballs?	Defeat Ultra Greedier as The Bastard
	Soul of Fiend	Defeat Boss Rush and Hush as The Bastard
	Golden Slot Machine	Defeat Mega Satan as The Bastard
	Malice	Defeat Delirium as The Bastard
	Hatred	Defeat Mother as The Bastard
	Modern Ouroboros	Defeat The Beast as The Bastard

Other Achievements

Icon	Name	Unlock Method
	Fiendish Foes	Install Fiend Folio
	Purple Putty	Kill 50 enemies with Immoral Minions
	>3	Unlock Immoral Hearts and then have 6 or more at once
	Devilled Egg	Kill Greg The Egg
	Skip Card	Skip 20 Rooms
	Zodiac Beggar	Enter a Planetarium
	Fraudulent Fungus	Have 3 or more Rotten Hearts at once
	Evil Sticker	Get the worst Cursed Penny payout
	Golden Cursed Penny	Pick up 50 Cursed Pennies
	Black Lantern	Kill Gravedigger in her mini-boss room in Cathedral
	Risk's Reward	Kill Psion in its mini-boss room in Sheol
	Flea of Meltdown	Kill Meltdown 3 times
	Flea of Deluge	Kill Meltdown 3 times
	Flea of Pollution	Kill Pollution 3 times
	Flea of Propaganda	Kill Pollution 3 times
	Flea Circus	Unlock Flea of Meltdown, Flea of Deluge, Flea of Pollution, and Flea of Propaganda
	Evil Beggar	Kill The Beast
	Soul of Random	Unlock half of all Soul Stones
	Mern	Build a Mern by getting 4 copies of Corn Kernel
	Bifurcated Stars	Enter a Treasure Room in Ascent that had been previously skipped
	The Deluxe	Unlock every type of Heart
	Queen of Clubs	Kill Singe
	13 of Stars	Chance to unlock when using a new TMTRAINER corrupted active item
	Kings of the Minor Arcana	Unlock Horse Pills, Golden Trinkets, and Golden Batteries
	King of Diamonds	Blow up 25 Fool's Gold Rocks
	Plague of Decay	Kill a Rotten Beggar
	Imp-Losion	Kill 50 enemies using Malice
	Soul of Golem	Use any Soul Stone as Golem
	Golden Reward Plate	Press 79 Reward Plates
	Glass Chest	Kill a boss in the Mirrored World
	Haunted Penny	Have 8 Book of Virtues wisps at once
	Shard of China	Die as China
	Dire Chest	Make a Dire Chest or Make The Middle Hand
	52 Deck	Trounce the dealer at a Poker Table 3 times and make him RAGEQUIT!
	The Right Hand	Defeat ??? while holding The Left Hand
	Morbus	Enter the Corpse
	Morbid Heart	Kill Mr. Dead
	Too Many Options!	Enter an Ultra Secret Room
	Tokens	Collect 1000 pickups in total
	Vending Machine	Use 5 different active items in one run

Prerequisite Unlocks

The following content does not have any Fiend Folio achievements tied to them, but still require one of the following achievements from the vanilla game to be obtained in order to encounter them:

Icon	Name	Unlock Method
	Azurite Spindown	Unlock Spindown Dice
	Loaded D6	Unlock The D6
	Dad's Legendary Golden Rock	Unlock Golden Trinkets
	Buried Fossil	Unlock The Forgotten