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Binding of Isaac: Rebirth Wiki

Added in Afterbirth
Questionmarkisaac.png For the item with a similar name, see The Hourglass.

Glowing Hour Glass is an activated item added in The Binding of Isaac: Afterbirth.

Effect[]

  • On use, Isaac will be returned to the previous room and everything that happened in the current room will be undone.
    • Health, bombs, coins, keys, cards/runes/pills, items, and trinkets will be restored.
    • Certain consumables (such as the Joker Joker) do not get restored.
    • Score and Time will reset, but about one second will be spent in unskippable animation after use.
    • Completion marks earned in the room will be removed.
    • Added in Afterbirth † Event counters will get restored (including Donation Machines, Greed Donation Machines, and 15►Eden's Blessing Eden's Blessing).

Notes[]

  • Removed in Repentance Does not return extra lives.
  • If the Glowing Hour Glass to go back in time to previous room, without moving to another room after the activation, each use will multiply some familiars that persist through rooms by duplicating them. (This is possibly a bug)
    • Familiars that can be multiplied:
    • There appears to be a limit to the number of familiars that can be gained through this method.
  • Using a Joker Joker and then the Glowing Hour Glass to return does not guarantee a Devil Room for every floor as the Joker card does not get refunded. The reason for this is that you immediately change rooms after the Joker card is used, as such reverting to before it was used is impossible.
  • Does not return health lost entering or leaving a Curse Room, as the health was lost in the previous room.
  • Removed in Repentance Does not return keys or health used to enter special rooms.
  • Does not preserve the Devil Room or Angel Room door if used to return to the Boss Room.
  • Does not turn a character back into another should they have been revived by 15►Ankh Ankh, 15►Lazarus' Rags Lazarus' Rags, or 15►Judas' Shadow Judas' Shadow.
    • Added in Afterbirth † Character changes are reverted by Glowing Hour Glass.
  • Added in Afterbirth † Does not affect the chance for a portal to The Void The Void to spawn (the portal will not spawn if it didn't spawn initially).
  • Removed in Afterbirth †Donations to the Donation Machine or Greed Machine are not reverted, and they can be reset into a working state once jammed.
    • Other counters not tied to your specific run, such as Slot Machines or Tinted Rocks destroyed, continue to accumulate, allowing easy unlocking of secrets such as the Counterfeit Penny Counterfeit Penny, the 15►D4 D4, and Conquest if you have access to infinite uses of the Glowing Hour Glass (see below).
  • With the Curse of the Blind, Glowing Hour Glass can be used to pick up or purchase an unknown item to see what it is, then decide whether or not to undo picking it up.
  • Using the Glowing Hour Glass to prevent picking the Glowing Hour Glass up while previously having had an active item will return the active item and discharge it completely.
  • No Damage Achievements are still available if the Glowing Hour Glass is used to reset damage.
    • Added in RepentancePerfection Perfection is still able to drop if the Glowing Hour Glass is used to reset damage.
  • Removed in Afterbirth † Isaac's temporary familiars (Blue Flies and Spiders) duplicate when using the Glowing Hour Glass.
    • If combined with 15►The Battery The Battery or 15►Sharp Plug Sharp Plug while Blue Spiders are present, this combo can generate an infinite army of Blue Spiders.
  • The Retro Vision Pill will continue to affect the game even after using the Glowing Hour Glass.
  • Removed in Repentance Can be used to unlock multiple achievements tied to the killing of certain bosses such as Mom's Heart / It Lives.
  • If there is a Lil' Battery in a Shop, the Glowing Hour Glass can be used infinitely, by entering the Shop without a charge and using the Lil' Battery to recharge and exit the shop. This is useful for duplicating temporary familiars or filling up the Donation Machine, among other uses.
  • Removed in Repentance Using the Glowing Hour Glass right after beating Mom's Heart / It Lives / Ultra Greed allows you to get additional Eden tokens.
  • Removed in Repentance If a new game is started and Eden Eden begins with this item, using it in the first room will cause the game to crash.
  • Does not remove collection page entries if it undoes collecting an item for the first time.
  • Added in Repentance Using the Glowing Hour Glass after beating Mom's Heart in Mausoleum Mausoleum/Gehenna Gehenna II will transport the player to the previous room without the Knife Pieces, but the door to Mom's Heart will also be closed. The following floor will be Womb Womb/Utero Utero/Scarred Womb Scarred Womb and not Corpse Corpse.
  • Added in Repentance Using the Glowing Hour Glass after entering a new floor will teleport you back to the boss room of the previous floor.
  • Added in Repentance Bethany Bethany's soul heart container does not get reset upon activating this item.
  • Added in Repentance If Tainted Jacob Tainted Jacob is hit by Esau, using the Glowing Hour Glass will return him to normal form in the previous room.
  • Added in Repentance The guaranteed angel room chance can be preserved if the item is used after entering the first devil room.
  • Added in Repentance If used during The Beast fight, it will teleport Isaac to the center of the room and have no further effect.
  • Added in Repentance May be helpful for finding Planetariums, as it lets the player effectively skip item rooms while also seeing if what's inside them is worth taking.
  • Added in Repentance The chance of a Planetarium generating on future floors can be preserved if Isaac enters one for the first time and then uses Glowing Hour Glass to leave, effectively allowing Isaac to reroll his Planetarium until a desired item is found.

Synergies[]

  • Removed in Afterbirth † ? Card ? Card: Allows for infinite usage as the ? Card gets refunded upon usage.
  • Added in Repentance15►4.5 Volt 4.5 Volt: Allows for infinite usage in rooms where a lot of damage can be dealt, most notably boss rooms.
  • 48 Hour Energy pill: Allows for infinite usage as the pill gets refunded upon use.
  • Removed in Repentance 15►9 Volt 9 Volt: Clearing any room is enough to instantly recharge the hourglass, allowing infinite tries for best outcome.
    • Added in Repentance With AAA Battery AAA Battery the hourglass is instantly recharged.
  • Removed in Afterbirth †15►The Battery The Battery: When the item is double charged and used it will also refund the used extra charge bar, making it possible to use it endlessly.
  • 15►Bum Friend Bum Friend: Using the Glowing Hour Glass after the Bum Friend has picked up coins but before it has spawned pickups will restore the coins in the room but will still cause the Bum Friend to drop pickups. This can be used to repeatedly generate pickups from the same set of coins.
  • 15►Curse of the Tower Curse of the Tower: If used quickly after taking damage, Troll bombs will spawn in the previous room. If you have the Safety Scissors Safety Scissors, these can be harvested as normal.
  • 15►Dark Bum Dark Bum: Using the Glowing Hour Glass after the Dark Bum has picked up hearts but before it has spawned Soul Hearts will restore the hearts in the room but will still cause the Dark Bum to drop Soul Hearts. This can be used to repeatedly generate Soul Hearts from the same set of hearts.
  • Added in Repentance15►Duality Duality: Time can be reversed while inside one deal to go into another.
  • Added in Repentance15►Eraser Eraser + Added in Afterbirth †15►Schoolbag Schoolbag: Using Glowing Hourglass to return to the previous stage will keep the charge Eraser received from entering the next stage.
  • 15►Habit Habit: Allows rooms to be repeated infinitely as long as Isaac has enough health to take Removed in Repentance two (Added in Repentance three) hits, which are refunded on use.
  • Added in Afterbirth †Hairpin Hairpin: If Hairpin is held while entering any Boss Room for the first time, Glowing Hourglass may be used indefinitely on said room to repeat the fight until you beat it.
    • Only applies after Booster Pack 5.
  • 15►More Options More Options: If used after entering the Treasure Room for the first time, upon reentering the room, one item will have changed places and another will be new, effectively making More Options a choice of 3 items instead of 2. If used a second time, the items change back.
  • Added in Afterbirth †15►Moving Box Moving Box: Using the Glowing Hour Glass after retrieving it from Moving Box will not deplete its charge. Allows for infinite usage as long as Moving Box is fully charged.
  • Added in Repentance15►Saturnus Saturnus: Using the Glowing Hourglass will activate the effect of Saturnus again, essentially allowing for double the amount of orbiting tears, if the player returns to a room, where the tears created by Saturnus were not destroyed.
  • 15►Sharp Plug Sharp Plug: Allows for infinite usage as long as you have more than 2 (Added in Repentance 1.5) full hearts as the hearts used to charge will be refunded upon use.

Interactions[]

  • Added in Repentance15►Bag of Crafting Bag of Crafting: The bag's contents will be reverted to its previous state.
  • Added in Repentance15►Book of Virtues Book of Virtues: Any wisps lost in the previous room will be restored, and an additional Glowing Hour Glass wisp will be added.
  • 15►Car Battery Car Battery: No effect.
  • Added in Afterbirth † / Removed in Repentance15►Void Void: It is impossible to absorb a Glowing Hour Glass pedestal without using the item and preventing it from having been absorbed.
    • Added in Repentance The Glowing Hour Glass is absorbed like normal. Subsequent uses of Void send Isaac back to the previous room reverting most changes, nullifying many other effects that Void may have absorbed. Energy is still reset back to full upon each use, allowing for infinite re-tries of any room. This does, however, prevent you from consuming any further powers as you will instead reset the room.

In-game Footage[]

Trivia[]

  • Prior to Booster Pack 5, Glowing Hour Glass would turn into 15►The Hourglass The Hourglass after being used 5 times.
    • Added in Repentance The icon of Glowing Hour Glass turning into the one of The Hourglass when it's not fully charged may be a nod to that.

Seeds[]

PC NDJQ D4GT (First floor Treasure Room)

PC SRVZ MGKQ (First floor Shop, quarter in Treasure Room)

PC Normal and hard modes onlyGreed mode only Y1WR PKCD (Eden spawn)

PC PFTJ B87Y (Second floor Shop for 7 cents)

PC Added in Afterbirth † 36WC YDYT (First floor Treasure Room)

XboxOne 07C6 H920 (Second floor Treasure Room)

PS4 3NBT BZ0W (Flooded Caves II Shop)

Switch YBW1 J3E0 (Eden Spawn)

Bugs[]

Bug Bug! Going back to a previous floor will cause some effects that were caused by going to the next floor to not be undone.
Bug Bug! Added in Repentance Going back to a previous floor twice in a row will cause 15►Lost Soul Lost Soul and 15►Blood Oath Blood Oath to activate their effects an additional time on that floor.
Bug Bug! Added in Repentance Using the infinite-uses interaction with 15►Void Void many times in a row (e.g. to create 15►Book of Virtues Book of Virtues wisps) may cause Isaac to be stuck stationary until the game is quit and reloaded, and sometimes causes the item charge to not be reset.


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