Greed Mode is a new game mode introduced in the Binding of Isaac: Afterbirth expansion.
In Greed Mode, each floor has a Curse Room, a Devil Room/Angel Room, a double-wide Shop, and an exit room all connected to a main double-height arena room with a button in the center. A Super Secret Room is also connected to one of the rooms. Up until the penultimate floor, an already unlocked Treasure Room with a silver doorframe and a normal locked treasure room are also available. The silver treasure room always gives items from the Boss pool. The sixth floor (The Shop) does not have any Treasure Rooms, but does have the Shop and Curse rooms. The final seventh floor has no waves and contains only three rooms, the largest of which contains the game mode's final boss.
When playing Greed Mode, a yellow coin () will appear on the HUD, below the consumables.
As there are no normal drops in Greed Mode, the shop becomes Isaac's primary source of items and pickups. Shops in Greed Mode automatically restock. The items for sale are a key, a heart pickup, a shop item, a boss item, and two random pickups, trinkets, or items from the treasure room pool.
The shop has a chance of containing a Restock Box, along with various pickups, machines, and beggars.
When the button is pressed, it turns red, grows spikes, and a timer appears underneath it. All doors are barred and waves of random enemies start spawning. The timer initially starts with 6 seconds left and will be increased by 1 second for every subsequent wave of enemies. Once the timer runs out or all enemies in the current wave are killed, another wave spawns. This continues until wave 8 is reached, Isaac dies, or Isaac presses the red button. Pressing the red button deals half a heart of damage to Isaac and causes waves to stop spawning, and once all remaining enemies are killed, the doors re-open. The button can then be re-activated to continue progressing through the waves.
At the start of each wave (with the exception of the nightmare boss wave), pennies are dropped on the ground, which Isaac can use in the shop to purchase items and pickups. Each new wave counts as a new 'room' for purposes of item charges, familiars dropping items, or the like. However, one-room temporary effects will remain, so it may be advisable to do all waves at once if you have a particularly good improvement, such as the effect of The Book of Belial.
2 and occasionally 3 pennies will drop for each of the first 8 waves. Upon completing the eighth wave, a skull appears on the button. Pushing the skull button starts the two boss waves, which grants access to the floor's exit room upon completion. A total of 9 coins will drop for these boss waves. Each boss wave will spawn one boss/mini-boss.
Upon completing the tenth wave of the floor, a pentagram appears on the button. Pushing the pentagram button starts the optional nightmare boss wave, which grants access to the devil/angel room when completed. Each nightmare boss wave can spawn multiple bosses/mini-bosses at once. No coins are dropped during the nightmare wave.
Items that activate upon entering a new room will not activate when a new wave starts, making many items far less useful or outright useless.
For the first 8 waves, the clock will start at a set time and then increase by 1 second for subsequent waves. For The Basement and The Caves, the clock starts at 6 seconds. For The Depths, the clock starts at 5 seconds. For The Womb, the clock starts at 4 seconds. For Sheol and The Shop, the clock starts back at 6 seconds again. The first boss wave is set at 30 seconds on all floors.
Greed Mode has seven total floors, five of which are based off of floors found in the main game. These floors are The Basement, The Caves, The Depths, The Womb, Sheol, a unique floor called The Shop, and the final boss floor. Each floor will spawn enemies and bosses native to that floor in the main game, except for The Shop, which has no counterpart outside of Greed Mode. Instead, The Shop spawns mostly Greed enemies, but can also spawn enemies from any floor. The Shop is the only normal floor which does not contain Treasure Rooms.
The Ultra Greed floor contains only three rooms: An empty starting room, a mini-boss room in which multiple Greeds, Super Greed, Wrath or Monstro will spawn, and the final boss room containing Ultra Greed. After Ultra Greed has been defeated, turning him into a golden statue, a Final Boss Chest to end the level and the Greed Machine will spawn. Isaac is given the chance to donate his remaining money to the Greed Machine, which will unlock several rewards including the Keeper character.
Greedier Mode is a harder version of Greed Mode. In Greedier Mode, fewer coins drop, enemies can become champions, and Ultra Greed has a second form, Ultra Greedier.
Greedier Mode starts off with 9 waves when the button is first pressed instead of 8. 1 and occasionally 2 pennies will drop for each of the first 9 waves. The boss waves remain at 2. A total of 10 coins will drop for these boss waves. The nightmare boss wave remains at 1 and no coins will drop.
For the first 9 waves, the clock will start at a set time and then increase by 1 second for subsequent waves. For The Basement, the clock starts at 8 seconds. For The Caves, the clock starts at 6 seconds. For The Depths, the clock starts at 4 seconds. For The Womb, the clock starts at 3 seconds. For Sheol and The Shop, the clock starts at 2 seconds. The first boss wave is set at 14 seconds on all floors.
The coin penalty for hitting the button before the waves are completed remains at 1 penny.
Greedier Mode unlockables are separate from Greed Mode unlockables; however, as of Booster Pack #5, completing Greedier Mode with a character will unlock the corresponding Greed Mode unlockable.
When playing Greedier Mode, a small, red coin () will appear on the HUD, below the consumables.
Donate 500 coins to the Greed Machine
to unlock it.
Completing Greedier Mode with a character will unlock the corresponding Greed Mode unlockable if it hasn't been unlocked.
- Completing all waves without pressing the stop button will maximize the total possible amount of coins.
- Flight will not prevent damage from the spiked stop button unless the player is The Lost.
- However, a penny is deducted from the next round of rewards if the button is pressed.
- Items with effects that only persist in the room are especially useful in Greed Mode. Complete all waves in one go to maximize their efficiency. Examples of such items include Box of Friends, Bloody Lust, Lusty Blood, The Pinking Shears, and Scissors.
- Avoid using the Credit Card on a shop until you are ready to move on to the next floor, as items will not restock unless you use a Restock Box.
- Being teleported by means of the Curse of the Maze can sometimes open the exit door without completing the floor, allowing you to skip large chunks of combat.
- Going to the Womb and beyond won't cause you to take 1 full heart of damage as normal.
- Killing all the enemies before the timer resets does not increase the amount of coins produced.
- The dead shop keepers have very low chance of dropping Steam Sale when bombed. If found early on it is extremely useful.
- The 2 of Diamonds card is very effective in Greed Mode as you can double your money, increasing your chance to get good items.
- There are setups that will allow near infinite purchases from the shop. Although not easy to obtain, they do help with obtaining Greed(ier) Mode achievements as your character will become overpowered. They also help to fill your Collection pages.
- Setup #1: 2 of Diamonds card, Blank Card, and the shop has to sell batteries. As long as you have enough coins to buy batteries, you can generate up to 99 coins easily. Obtaining Chaos will allow access to Devil and Angel room item pools allowing for a grossly overpowered character. Once an item pool has been depleted, then Breakfast will appear. Beware of Little Baggy as you will lose your 2 of Diamonds card if picked up (Unless you already have Starter Deck).
- Setup #2: Use Diplopia on Steam Sale. This will make all the items for free.
- Setup #3: Use Crooked Penny on Steam Sale. Same effect as #2.
- D20 is extremely useful if the shop on the floor contains a battery. Clear all the waves but do not pick up the coins, then re-roll them, open any chests and sacks that spawn, and repeat the process.
- When doing this, make sure you have a full charge on the D20 before you start opening chests, already-open chests re-roll into pickups with the D20.
- In the Womb, It Lives can spawn even if it hasn't been unlocked yet. 
- In Greedier Mode, after defeating Ultra Greedier, all poops (destroyed, damaged or intact) will be converted into golden poops upon the room converting to gold.
- Due to this, one could use A Card Against Humanity before defeating Ultra Greedier, so that once the room has been converted, the player has an overwhelming amount of money to donate to the Greed Donation Machine until it jams.
- Furthermore, Using A Card Against Humanity in the Ultra Greed fight can trap the Gapers after Key Coins appear, preventing Ultra Greed from attacking. If in Greedier Mode, the poops spawned will stay until the end of the Ultra Greedier fight where they will be converted into Golden Poops. For this reason, it may be an effective strategy to bring A Card Against Humanity into the Ultra Greed/ier fight, in order to both immobilize Ultra Greed and create an overwhelming amount of money to be donated into the Greed Donation Machine in Greedier Mode.
- Common display resolutions, such as 1920x1080 with aspect ratio 16:9, will show only part of the Arena in fullscreen mode. Switching to windowed mode and then resizing the window makes it possible to keep an eye on the entire Arena while playing.
- Anemic: Getting hit once activates the blood trail until Isaac leaves the room.
- Betrayal: Charms every enemy when hit, allowing an entire wave to be cleared at the cost of one hit.
- The Book of Belial: Although the effect does not stack with itself, the damage increase lasts until you leave the room.
- Book of the Dead: Spawns bone orbitals or charmed Bonies when there are killed enemies in a room. Making this item especially useful after the first 8 rounds and before the boss rounds.
- Box of Friends: Duplicated familiars last until Isaac leaves the room, making it possible to use Box of Friends repeatedly to generate lots of duplicates.
- Brown Nugget: Because turret flies last until Isaac leaves the room, Brown Nugget can be used repeatedly to create lots of turrets.
- Dad's Key: Essentially allows Isaac to enter the treasure room for free.
- Dad's Ring: Petrifies enemies that are close to Isaac and stops enemies from surrounding Isaac with no reprieve.
- Dead Bird: Getting hit once activates Dead Bird until Isaac leaves the room.
- Jaw Bone: Familiar that will retrieve pickups for Isaac.
- Milk!: Getting hit once decreases tear delay until Isaac leaves the room.
- Sprinkler: Sprinklers last until Isaac leaves the room, allowing multiple sprinklers to be placed.
- Wooden Nickel: Allows Isaac to easily gain a lot more money very quickly, as it can be used once per wave.
Edmund McMillen's sketch of the Greed Mode layout
- Isaac’s sin is confirmed to be greed, hence the creation of Greed Mode.
- Ultra Greed’s theme, named “Chorus Mortus”, is a remix of the main menu theme.