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 Locked 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).

 Taking damage from the spikes doesn't reduce the odds of getting a Devil or Angel room.

The base chance of a Sacrifice Room being generated is 1/7 (~14%). If Isaac's total health 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.

## Layouts

* (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 ), 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.
* Isaac must take damage on the spikes for the rewards to pay out. Invulnerability, shields, and effects that block damage (, , the Dog Mode Special Seed etc.) will not trigger a sacrifice.
	+ Temporary characters created by , , and  can be used to make sacrifices without Isaac himself having to take damage.
* The  prevents the Sacrifice Room from functioning.
* has a chance to re-roll the spike in the middle of a Sacrifice Room, making it unusable.
* Bone Hearts cannot be broken if filled with at least a Half Red Heart, even if a full heart of damage is taken. This can be abused to repeatedly pay a half-red heart for each use of a Sacrifice Room.
* Sacrifice Rooms do not naturally appear in the Chest, Dark Room, or The Void.
	+ They can, however, be generated in red rooms, such as those created by the .
	+ Sacrifice Rooms generated by using  in the Dark Room will warp Isaac to the first room of the floor when used enough, rather than warping to a new instance of Dark Room.
* If more than one Sacrifice Room is created on one floor with  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 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.
* Similarly, separate spikes even in the same sacrifice room, if spawned with the , have their own individual sacrifice counters.
* Entering a Sacrifice Room while holding  will cause the spikes to be retracted into the ground. Dropping the trinket and re-entering the room will cause the spikes to reappear.

## 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 .
* Dying in a Sacrifice Room with the  will reveal puzzle pieces used to unlock the  The Lost.

## Notes on Afterbirth Sacrifice Rooms

* Losing red hearts due to the spikes will reduce the chance for a Devil Room or Angel Room to appear.
* 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.
* 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  will unlock  The Lost (except during a Challenge or Victory Lap).
* Spikes in the sacrifice room normally deal one full heart of damage.
	+ However, if you have half a soul heart in addition to red hearts, the damage will remove the half soul heart and not deal any red heart damage.
	+ , , 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  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  can be used on low health in an attempt to acquire soul hearts.

## Unlockable Achievements

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