Sacrifice Room

Sacrifice Rooms are special rooms that contain a set of spikes in their center. Isaac can damage himself on the spikes for a chance to spawn a Chest or a Golden Chest. The chance is determined by the seed, meaning Isaac must damage himself on the spikes a set number of times for a Chest to spawn. Sacrifice Rooms were reworked, with a wide variety of possible rewards (shown below).

The base chance of a Sacrifice Room being generated is 1/7 (~14%). If Isaac's total heath is equal to or greater than his total red heart containers, an additional 1/4 chance applies for a total of 5/14 (~36%).

Sacrifice Rooms are mutually exclusive with Dice Rooms. If a Sacrifice Room is to be generated, it has a 1/50 base chance to be replaced by a Dice Room, plus an additional 1/5 chance for a total of 27/125 (~22%) if Isaac has 2 or more keys.

Rewards

The payouts only depend on the number of sacrifices made. The number of sacrifices is reset to 0 when Isaac goes to the next floor.

№ of sacrifices on Current Floor	Chance	Reward
1st / 2nd	50%	Nothing
	50%	1 Penny
	100%	1 Bomb (Only if the first floor boss has been defeated in less than one minute and Isaac has no bombs, to help obtain Broken Shovel)
3rd	33%	Nothing
	67%	"You feel blessed!" (increased chance to receive an Angel Room over a Devil Room for the current floor) Does not increase the chance of a Devil/Angel Room after defeating a boss, only the chance of getting an Angel Room over a Devil Room. Can cause an Angel Room to spawn even if Isaac has already taken a deal with the Devil. Gives a smaller bonus than the "You feel blessed!" effect below. A guaranteed Angel Room replacement if this occurred in a Chapter 1 XL floor. If Isaac has not yet encountered a Devil/Angel Room yet, guarantees the first room encountered to be an Angel Room.
4th	50%	Nothing
	50%	1 random chest (The type of chest is governed by the same mechanic as room drops. Thus, regular chests are more likely to spawn than any other kind of chest.)
5th	33%	3 Pennies (These coins do not have a chance to spawn as a nickel or a dime.)
	67%	"You feel blessed!" (Same conditions as 3rd sacrifice but providing a stronger modifier.)
6th	33%	Teleport to the Devil/Angel Room. (If the floor's Devil/Angel Room has not been spawned yet, an Angel Room is guaranteed to spawn — even if a Devil Deal has already been taken.)
	67%	1 random chest (The type of chest is governed by the same mechanic as room drops. Thus, regular chests are more likely to spawn than any other kind of chest.)
7th	33%	1 random Angel Room item. if a Deal with the Devil was taken previously, Redemption will spawn instead if unlocked.
	67%	1 Soul Heart
8th	100%	6 Troll Bombs
9th	100%	Uriel battle
10th	50%	7 Soul Hearts
	50%	30 Pennies
11th	100%	Gabriel battle
12th and onwards	50%	Nothing
	50%	Teleport directly to the Dark Room.

Layouts

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  (Rare)

Notes

• The sacrifice rewards are determined ahead of time, not when Isaac steps on the spikes.
  • Received items/trinkets can be changed, however. If Isaac checks the items and resets (such as with the Glowing Hour Glass), he can find that item on the same floor, then redo the sacrifice to force a different item to spawn.
  • Resetting will reset Isaac's number of sacrifices to what it was prior to his reset unless stated otherwise.
• Spikes in a Sacrifice Room will deal damage even when flown over, so Isaac can use them even with Flight.
• Invincibility and shields will not trigger a sacrifice (including Holy Mantle).
• The Callus prevents the Sacrifice Room from functioning.
• Sacrifice Rooms do not naturally appear in the Chest, Dark Room, or The Void.
• Sacrifice Rooms won't teleport Isaac to the Dark Room during a challenge or daily challenge that does not end there, thus nothing will happen from the 12th sacrifice onward.
• If more than one Sacrifice Room is created on one floor with Red Key or equivalent effects, each Sacrifice Room has its own sacrifice counter. For example, doing 3 sacrifices in one room, then 3 in another gives Isaac the 1st to 3rd effects from both rooms, instead of 1st to 3rd, then 4th to 6th. Additionally, performing more sacrifices in the first room again will count up from 4th; the count is not reset by using another room.
• Sacrifice Rooms generated by using Red Key in the Dark Room will, when used enough times, teleport Isaac to a new instance of the Dark Room. This effectively generates a new floor.
• Entering a Sacrifice Room while holding Flat File will cause the spikes to be retracted into the ground. Dropping the trinket and re-entering the room will cause the spikes to reappear.
• If another non-co-op character takes damage on Sacrifice Room spikes, such as by using Soul of the Forgotten or Soul of Jacob and Esau, it will spawn 7 troll bombs every time they take damage. This still moves the room's sacrifice counter up for each hit.

Notes on Rebirth Sacrifice Rooms

• Only one chest can be received per Sacrifice Room.
• Taking damage down to half a red heart will always drop a chest. (Because ??? cannot have Red Heart containers, dropping down to half a heart does not guarantee a drop.)
• Dying on the spikes guarantees a chest, which can be useful if Isaac is low on health and has more lives from something like Dead Cat.
• Dying in a Sacrifice Room with the Missing Poster will reveal puzzle pieces used to unlock the The Lost.

Notes on Afterbirth Sacrifice Rooms

• If Isaac receives both of the "You feel blessed!" effects, they will stack for a 65% Angel Room generation chance.
• The amount of health Isaac has left after taking a sacrifice does not affect the payout probabilities.
• Losing red hearts due to the spikes will reduce the chance for a Devil Room to appear.
• Isaac's Luck stat does not affect the payout probabilities.
• If Uriel or Gabriel spawn, they can be despawned by exiting the room.
• While Uriel and Gabriel can normally fly over spikes without taking damage, they will take damage from Sacrifice Room spikes.
• Dying in a Sacrifice Room while holding Missing Poster will unlock The Lost (except during a Challenge or Victory Lap).
• The Wafer, Cancer, and the Percs pill reduce the spikes' damage to half a heart, allowing Isaac to make more sacrifices.
• If using the BASE MENT seed, the Dark Room teleport can escape the infinite Basement floors.
• Even if The Negative isn't unlocked, Isaac can still teleport to the Dark Room.
  • This allows Isaac to challenge The Lamb without facing Satan, Mom's Heart/It Lives, or even Mom.
• Dying and respawning does not reset the number of sacrifices made, so Dead Cat can be used on low health in an attempt to acquire soul hearts.

Unlockable Achievements

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  The Lost - It's complicated
  Die in a Sacrifice Room while holding Missing Poster.

Bugs

Bug!	Found HUD will incorrectly display Angel Room generation chance at 100% when receiving either of the "You feel blessed!" effects.

Bug!	If Isaac touches a Red Chest, the game will determine whether or not he gets a Devil/Angel Room that floor even if he doesn't teleport, which nullifies the Angel Room chance boosts and can cause him to teleport into a Devil Room instead of an Angel Room on the 6th use.