- Upon use, sacrifices up to 2 familiars and spawns an item from the Devil Room pool for each familiar sacrificed.
- The order in which the familiars were obtained does not matter; it picks 2 at random to sacrifice.
- If Isaac has no familiars, no Blue Flies, and no Blue Spiders, the item will do nothing and will not be consumed.
- Even if Isaac doesn't have any familiars, if he has a single fly, spider, or locust, the item will be consumed.
- If the Devil Room pool has no items left, one or two copies of Pentagram are spawned.
- When playing Greed mode, the normal Devil Room pool is still used, instead of the Greed mode pool.
- In addition to the familiars, any Blue Flies, Blue Spiders, or Locusts will be converted to 1 Penny each.
- On use, causes a brief Curse of Darkness effect for a few seconds.
- If playing as Lilith, the Incubus familiar cannot be sacrificed.
- Charmed and friendly enemies cannot be sacrificed.
- Any Pretty Flies are counted as a single sacrifice.
- Familiars spawned from Trinkets like Isaac's Head can be sacrificed, destroying the trinket in the process.
- Brown Nugget: Spawned fly turrets count as familiars for sacrificing; although dropping the Brown Nugget will despawn the last fly turret, older ones will remain and can be sacrificed.
- Spawned fly turrets count as regular blue flies for sacrificing, and thus are converted to pennies.
- Guardian Angel / Seraphim / Sworn Protector: 2 Black Hearts will also drop.
- Isaac's Heart: Can remove the Isaac's Heart familiar while the item remains, making Isaac invulnerable.
- Monster Manual: Summoned familiars can be sacrificed since they persist for the entire floor, even without holding the item.
- Plum Flute: Using Plum Flute, then using Sacrificial Altar will remove the Baby Plum spawned and spawn an item. The Plum Flute is not removed upon doing this, and subsequent usage of Plum Flute still summons Baby Plum normally.
- Void: When absorbed by Void, the one time use no longer applies, unlike other one time use active items. Familiars can be sacrificed with every activation of Void.
- 7 Seals: Cannot be sacrificed in itself, but Locusts can be sacrificed for one coin each, much like Blue Flies.
- Abyss: Locusts created from Abyss are counted as familiars and can be sacrificed as normal.
- Ball of Bandages / Cube of Meat : The altar consumes the whole familiar, up to 4 cubes or balls at a time. If more than 4 are available, they count as other familiar(s) that may be separately chosen for sacrifice.
- Best Bud / Dead Bird / Eve's Bird Foot / Bird Cage: These familiars can be sacrificed only when they're active.
- Book of Virtues: Converts each Wisp into a Half Red Heart. Spawns a red Wisp and a black Wisp after the sacrifice.
- Box of Friends / Monster Manual / Umbilical Cord: The familiars generated by these items can be sacrificed and turned into items.
- Car Battery: No effect; only spawns one item per familiar sacrificed, and can only sacrifice up to 2 familiars.
- Chaos: The Altar ignores the effects of Chaos, always spawning items from the Devil Room pool instead of a random pool.
- Conjoined: The transformation will be lost if Isaac has less than three items needed after using Sacrificial Altar.
- Dirty Mind: Each Dip spawned by Dirty Mind is turned into a coin, regardless of type.
- Giant Cell: Converts all micro-Isaacs into one coin each upon use.
- Halo of Flies: Both flies created by this item are counted as a single sacrifice each, due to the fact that they are counted as pretty flies.
- The Intruder: The Intruder can be sacrificed even while it's in Isaac's head.
- Lemegeton: Created familiars can be sacrificed. Additionally, converts each ghost into a Half Soul Heart. The passive item effects granted by the familiars is retained for the duration of the floor.
- Lil Delirium: Lil Delirium may be sacrificed, but the item is not removed. The familiar will return once another familiar is gained or lost, or the run is quit and resumed.
- The Pinking Shears: Body familiars that are spawned by this item can be sacrificed by switching between the Pinking Shears and Sacrificial Altar. However, the body familiars reappear when picking one of the spawned items up.
- Quints: The item will be lost, and each spawned familiar counts as one sacrifice.
- Star of Bethlehem: Although not readily apparent as a familiar, the Star can be sacrificed. It will be destroyed even if it is not currently in the same room.
- Sumptorium: Each Clot spawned by Sumptorium is turned into a coin, regardless of type.
- The Twins: Copied familiar cannot be sacrificed, and will disappear with the original familiar.
- Zodiac: A Gemini familiar granted by Zodiac can be sacrificed without losing the item.
The following familiars, followers, and orbitals cannot be sacrificed:
- 7 Seals
- Angelic Prism
- Angry Fly
- Blood Oath
- Bomb Bag
- Daddy Longlegs
- Dark Bum
- Dead Cat
- Decap Attack
- Found Soul
- GB Bug
- Guppy's Hair Ball
- Hallowed Ground
- Holy Water
- Isaac's Heart
- Jaw Bone
- Juicy Sack
- Key Piece 1
- Key Piece 2
- Knife Piece 1
- Knife Piece 2
- Lil Chest
- Mom's Razor
- Mom's Toenail
- My Shadow
- Mystery Egg
- Mystery Sack
- Paschal Candle
- Pointy Rib
- Poke Go
- The Relic
- Rune Bag
- Sack of Pennies
- Sack of Sacks
- Sacrificial Dagger
- Samson's Chains
- Slipped Rib
- Spear of Destiny
- Spin to Win
- Sacrificial Altar was added in Booster Pack #5, after the initial release of the DLC.
- Sacrificial Altar is based on this Steam Workshop item by Niro and PJJLegend, originally known as Satanic Ritual.
Sacrificial Altar's appearance in the original Steam Workshop mod.
|Bug!||If used to sacrifice Succubus while Isaac is in its dark aura, the damage multiplier will remain active for the remainder of the floor.|
|Bug!||All items created by Lemegeton will still grant their effects after being sacrificed until Lemegeton is used again.|
|The Binding of Isaac: Rebirth|
|Achievements||Attributes||Bosses||Cards and Runes||Challenges||Chapters|