Character mechanics guides

The eight-item limit

Manage eight passive slots, pick the visible pedestal option and decide which effect to replace.

The highlighted item is the one you will drop.

Bag of Crafting

Turn ordinary pedestals into supplies, reserve useful pickups and build an eight-component crafting preview.

A bagged pickup is no longer available for normal collection.

Flip and two inventories

Keep two health bars and inventories useful, prepare Flip charges and protect the hidden pedestal counterpart.

A room clear changes your form without flipping its pedestals.

Blood clots and Sumptorium

Learn when firing creates clots, what Sumptorium recalls and why a lost clot cannot be treated as stored healing.

Holding fire can spend health while you concentrate on the enemy.

Blood charges and Lemegeton

Separate red-heart charges from Soul health and understand the temporary item effects supplied by Lemegeton.

A wisp effect lasts only while that wisp survives.

Poop queue and Hold

Use the leftmost poop effect, understand the separate supply count and store a useful effect in Hold for later.

The next queue effect can be hazardous instead of a normal placed bomb.

Dark Arts timing

Time Dark Arts, tag enemies and shots, then leave yourself room to dodge when its protection ends.

Watch the exit position, not only the targets you can cross.

Automatic Berserk

Recognize automatic Berserk, extend its timer through kills and check your health before the mode ends.

Watch the remaining duration and actual health.

Sneeze, curse and beam

Use the charging sneeze to curse nearby enemies, follow with the thin beam and remember that you start without flight.

The sneeze has short reach; the wings do not grant flight.

Launch, hold and recall

Choose between a fetus launch and sustained fire, then recall it to prepare the next launch.

Launching and holding fire create different attack positions.

Abyss and permanent locusts

Compare taking an item with making a locust, and check linked choices and room triggers before using Abyss.

Abyss can consume several unlinked pedestals in the same room.

Thrown body and Soul safety

Throw the invulnerable body, protect the moving Soul and check where bombs appear before spending one.

The Soul takes damage even when the thrown body is safe.

Leaking health and lethal hugs

Manage leaking health, collect brief healing drops and distinguish boosted Yum Heart healing from ordinary heart pickups.

Watch the protected red-heart portion and the healing route.

Coin healing and item prices

Balance coin healing, disappearing enemy drops and priced item choices without treating every penny as spendable money.

A healing Penny does not also add money to the counter.

Damage rerolls and Birthright

Recognize damage-triggered rerolls, separate self-damage payments and understand which acquired items Birthright protects.

A weapon, active item or health effect may change after a qualifying hit.

Holy Card protection

Manage Holy Card protection, keep a spare when possible and distinguish one-use shields from recurring Holy Mantle.

Changing rooms does not restore a spent Holy Card shield.

Dark Esau and ghost form

Chain Dark Esau, prepare for his release and understand why ghost-form health will not protect you on this floor.

A released chain causes a charge; a faded health bar is not protection.

Soul Charges and Book of Virtues

Turn Soul Hearts into active charges, protect your red health and understand how Book of Virtues works with another active.

A Soul Heart adds fuel, not a protective health layer.

Bone body and tethered Soul

Switch between the bone body and tethered Soul, route heart pickups and avoid treating one form as a spare life.

The body's remaining health does not save a Soul killed by damage.

Coin Hearts and starting upgrades

Manage Coin Hearts, check permanent starting upgrades and use Wooden Nickel without assuming it guarantees a healing coin.

Healing money is not spending money, and Wooden Nickel can produce nothing.

Unlocked Mantle and Eternal D6

Check the Lost's Mantle unlock, retreat after its shield breaks and weigh Eternal D6 against losing a pedestal.

The recurring starting Mantle requires the Greed Donation unlock.

Two bodies and separate builds

Assign items and healing to the right brother, keep both bodies safe and check both bomb placements before using one.

Separate health and items share one run and pickup counter.

Revival and the next floor

Understand Lazarus's floor-based revival, reduced heart capacity and lasting damage gain before risking another hit.

The innate revival stays spent until the next floor.

Red health and Whore of Babylon

Learn Eve's low-red-health threshold, healing timing and Birthright, while separating Dead Bird from the damage state.

One full Red Heart or less can activate the damage state.

Incubus and temporary familiar copies

Position Incubus, use room-long Box of Friends copies and learn why repeated uses add rather than double the army.

The temporary copies leave when you leave the room.

Void absorption and stored activations

Separate passive absorption from stored active effects, then plan Void uses around the charge and items actually in the room.

Absorption consumes the pedestal rather than keeping its original effect.

D6 unlock and pedestal choices

Check Isaac's D6 unlock, distinguish room pedestals from held items and choose one face of a Birthright pedestal.

The D6 is a starting upgrade, not part of every fresh profile.

Yum Heart and healing reserves

Use Yum Heart, distinguish healing from capacity and check Magdalene's unlocked Full Health pill before spending it.

A heal needs missing red health; it does not add ordinary capacity.

Lucky Foot and Paper Clip

Use Cain's Lucky Foot pill conversion, check the Paper Clip unlock and keep keys for doors the trinket cannot open.

Paper Clip frees Golden Chests, not every locked entrance.

Book of Belial and a small health reserve

Time Book of Belial, check the end of its room bonus and understand Birthright before replacing the active item.

The book adds damage, not healing or invulnerability.

Soul health and The Poop

Learn Blue Baby's health-up conversion, turn ordinary poop into flies and separate Birthright health gains from red healing.

Red containers become Soul Hearts; ordinary red healing cannot refill them.

Bloody Lust and floor transitions

Understand Samson's Bloody Lust trigger, carry its bonus between rooms and check what resets when entering a new floor.

Bloody Lust rewards damage taken; it does not prevent the hit.

Flight and short beam positioning

Learn Azazel's short charged beam, use flight for positioning and see why a Black Heart start does not forbid red containers.

Flight changes movement; it does not make enemy shots harmless.

Random starts and Eden Tokens

Check Eden's token cost, inspect the random starting tools and choose one of the three items offered by ordinary Birthright.

The starting build is random; the first decision can still be deliberate.