Polluted Cistern // Dim Oubliette

Card text

Whenever one or more cards are put into your graveyard from your library, each opponent loses 1 life for each card type among those cards.

(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Market price

Latest aggregated market price for the normal finish of this printing: $0.82 (as of 2026-11-03).

The figure covers this printing only; other printings carry their own price on their own page.

Format legality

Legality of Polluted Cistern // Dim Oubliette by format. Formats in which it is not legal are not listed.

Official rulings

The 8 most recent official rulings for Polluted Cistern // Dim Oubliette, newest first.

• 2024-09-20 Each Room card has two names. If an effect instructs you to choose a card name, you may choose one of those names, but not both.
• 2024-09-20 If a Room enters from any zone other than the stack, it will enter with both halves locked.
• 2024-09-20 An ability that triggers "when you unlock this door" triggers when that door becomes unlocked. This can happen one of two ways: (1) the door becomes unlocked on the battlefield or (2) the door becomes unlocked as the Room enters the battlefield because you cast the corresponding half. In the latter case, since the door becoming unlocked is what causes the ability to trigger, effects that cause abilities that trigger when a permanent enters to trigger an additional time (such as that of Panharmonicon) won't apply.
• 2024-09-20 Some abilities allow you to lock a door of a Room you control. You can't choose to lock a door that's already locked with such an ability. If such an ability requires a target, you can target a Room even if both of its doors are locked, but the ability won't do anything when it resolves.
• 2024-09-20 Room cards have two card faces with a shared type line on a single card. The characteristics of the door you didn't cast are ignored while the spell is on the stack.
• 2024-09-20 While in any zone other than the stack or the battlefield, a Room card's characteristics are a combination of its two doors. For example, Bottomless Pool // Locker Room has a mana value of 6 while it's in your library. If an effect allows you to search your library for a card with mana value 4 or less, you can't find Bottomless Pool // Locker Room.
• 2024-09-20 An ability that triggers "whenever you fully unlock a Room" triggers when a door becomes unlocked and the other door of that Room is already unlocked, or when both doors of that Room become unlocked simultaneously.
• 2024-09-20 If a spell or ability would create a copy of a Room spell on the stack, the copy retains the choice of which door was cast but also retains the full characteristics of the spell. The characteristics of the door that wasn't cast are still ignored while the copy is on the stack, and when the copy resolves, the token it becomes will enter with the appropriate door unlocked.

Similar cards

Other enchantment cards with a black colour identity, ranked by how often they appear in Commander decks.

• Phyrexian Arena
• Black Market Connections
• Animate Dead