Commander creatures you own have "Room abilities of dungeons you own trigger an additional time."

Astral Cornucopia enters the battlefield with X charge counters on it. {T}: Choose a color. Add one mana of that color for each charge counter on Astral Cornucopia.

{T}: Add {U} or {B}. {U}{B}: Dimir Keyrune becomes a 2/2 blue and black Horror artifact creature until end of turn and can't be blocked this turn.

{T}: Add {C}. {3}, {T}: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

Dungeoneer's Pack enters the battlefield tapped. {2}, {T}, Sacrifice Dungeoneer's Pack: You take the initiative, gain 3 life, draw a card, and create a Treasure token. Activate only as a sorcery. (A Treasure token is an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Climb Over — {T}: Target Wall can't block this turn. Tie Up — {3}, {T}: Target creature doesn't untap during its controller's next untap step. Rappel Down — {4}, {T}: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

When Sarevok's Tome enters the battlefield, you take the initiative. {T}: Add {C}. If you have the initiative, add {C}{C} instead. {3}, {T}: Exile cards from the top of your library until you exile a nonland card. You may cast that card without paying its mana cost. Activate only if you've completed a dungeon.

When Thieves' Tools enters the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.") Equipped creature can't be blocked as long as its power is 3 or less. Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

When Trailblazer's Torch enters the battlefield, you take the initiative. Whenever equipped creature becomes blocked, it deals 2 damage to each creature blocking it. Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

{4}, Sacrifice Treasure Chest: Roll a d20. 1 | Trapped! — You lose 3 life. 2—9 | Create five Treasure tokens. 10—19 | You gain 3 life and draw three cards. 20 | Search your library for a card. If it's an artifact card, you may put it onto the battlefield. Otherwise, put that card into your hand. Then shuffle.

Flying When Aarakocra Sneak enters the battlefield, you take the initiative.

When Clattering Skeletons dies, venture into the dungeon. (Enter the first room or advance to the next room.)

Consuming Aberration's power and toughness are each equal to the number of cards in your opponents' graveyards. Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.) Sacrifice a creature: Regenerate Dimir House Guard. Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

When Displacer Beast enters the battlefield, venture into the dungeon. (Enter the first room or advance to the next room.) Displacement — {3}{U}: Return Displacer Beast to its owner's hand.

Flying When Eccentric Apprentice enters the battlefield, venture into the dungeon. (Enter the first room or advance to the next room.) At the beginning of combat on your turn, if you've completed a dungeon, up to one target creature becomes a Bird with base power and toughness 1/1 and flying until end of turn.

When Feywild Caretaker enters the battlefield, you take the initiative. At the beginning of your end step, if you have the initiative, create a 1/1 blue Faerie Dragon creature token with flying.

Haste Goblin spells and Rogue spells you cast cost {1} less to cast.

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.) At the beginning of your end step, if you have the initiative, draw a card. Draw another card if you've completed a dungeon. Choose a Background (You can have a Background as a second commander.)

Whenever Krydle of Baldur's Gate deals combat damage to a player, that player loses 1 life and mills a card, then you gain 1 life and scry 1. Whenever you attack, you may pay {2}. If you do, target creature can't be blocked this turn.

Maga, Traitor to Mortals enters the battlefield with X +1/+1 counters on it. When Maga enters the battlefield, target player loses life equal to the number of +1/+1 counters on it.

Whenever a creature an opponent controls dies, exile it with a hit counter on it. Assassins, Mercenaries, and Rogues you control have deathtouch and "Whenever this creature deals combat damage to a player, you may remove a hit counter from a card that player owns in exile. If you do, draw a card and create two Treasure tokens."

Flying Whenever you create or sacrifice a token, each opponent loses 1 life.

{3}{U}, {T}: Exile another target creature you control, then return that card to the battlefield under your control.

When Netherborn Phalanx enters the battlefield, each opponent loses 1 life for each creature they control. Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Lifelink When Passageway Seer enters the battlefield, you take the initiative. At the beginning of your end step, if you have the initiative, put a +1/+1 counter on Passageway Seer.

Ninjutsu {1}{U} ({1}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) Whenever one or more Ninja or Rogue creatures you control deal combat damage to a player, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

When Ravenloft Adventurer enters the battlefield, you take the initiative. If a creature an opponent controls would die, instead exile it and put a hit counter on it. Whenever Ravenloft Adventurer attacks, if you've completed a dungeon, defending player loses 1 life for each card they own in exile with a hit counter on it.

Deathtouch When Rilsa Rael, Kingpin enters the battlefield, you take the initiative. Whenever you attack, target attacking creature gains deathtouch until end of turn. If you've completed a dungeon, that creature also gets +5/+0 and gains first strike and menace until end of turn.

{2}{B}, Sacrifice a creature: Create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.") Sacrifice three Treasures: Draw a card.

Defender {4}{U}: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

Whenever Shortcut Seeker deals combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)

Flying White spells and black spells you cast cost {1} less to cast.

When Tomb of Horrors Adventurer enters the battlefield, you take the initiative. Whenever you cast your second spell each turn, copy it. If you've completed a dungeon, copy that spell twice instead. You may choose new targets for the copies. (A copy of a permanent spell becomes a token.)

Menace (This creature can't be blocked except by two or more creatures.) When Underdark Explorer enters the battlefield, you take the initiative.

When Vicious Battlerager enters the battlefield, you take the initiative. Spiked Retribution — Whenever Vicious Battlerager becomes blocked by a creature, that creature's controller loses 5 life.

Deathtouch Whenever Yuan-Ti Fang-Blade deals combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)

Yuan-Ti Malison can't be blocked as long as it's attacking alone. Whenever Yuan-Ti Malison deals combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)

Enchant creature Enchanted creature has flying and "Whenever this creature deals combat damage to a player, venture into the dungeon." (Enter the first room or advance to the next room.)

Enchant creature When Precipitous Drop enters the battlefield, venture into the dungeon. (Enter the first room or advance to the next room.) Enchanted creature gets -2/-2. It gets -5/-5 instead as long as you've completed a dungeon.

(Gain the next level as a sorcery to add its ability.) Whenever a creature you control deals combat damage to a player, exile the top card of that player's library face down. You may look at it for as long as it remains exiled. {1}{U}{B}: Level 2 Creatures you control have menace. {2}{U}{B}: Level 3 You may play cards exiled with Rogue Class, and you may spend mana as though it were mana of any color to cast those spells.

Counter target creature or planeswalker spell. Venture into the dungeon. (Enter the first room or advance to the next room.)

Return target permanent to its owner's hand. Its controller loses 3 life. Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Return X target creature cards from your graveyard to your hand.

Choose one — • Counter target sorcery spell. • Destroy target creature with power 2 or less. • Look at the top three cards of target player's library. Put one back and the rest into that player's graveyard.

Choose one — • Counter target spell with mana value less than or equal to the number of cards in its controller's graveyard. • Destroy target creature with mana value less than or equal to the number of cards in its controller's graveyard.

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

You may cast target instant or sorcery card from an opponent's graveyard without paying its mana cost.

Counter target spell unless its controller discards their hand. Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Choose two — • Counter target noncreature spell. • Return target permanent to its owner's hand. • Target creature gets -3/-3 until end of turn. • Destroy target planeswalker.

Exile X target cards from target player's graveyard. For each card exiled this way, that player loses 1 life and you gain 1 life.

Barad-dûr enters the battlefield tapped unless you control a legendary creature. {T}: Add {B}. {X}{X}{B}, {T}: Amass Orcs X. Activate only if a creature died this turn.

Castle Vantress enters the battlefield tapped unless you control an Island. {T}: Add {U}. {2}{U}{U}, {T}: Scry 2.

{1}, {T}: Add {U}{B}.

Dimir Guildgate enters the battlefield tapped. {T}: Add {U} or {B}.

Dismal Backwater enters the battlefield tapped. When Dismal Backwater enters the battlefield, you gain 1 life. {T}: Add {U} or {B}.

Dungeon Descent enters the battlefield tapped. {T}: Add {C}. {4}, {T}, Tap an untapped legendary creature you control: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

({T}: Add {U}.)

Jwar Isle Refuge enters the battlefield tapped. When Jwar Isle Refuge enters the battlefield, you gain 1 life. {T}: Add {U} or {B}.

Memorial to Folly enters the battlefield tapped. {T}: Add {B}. {2}{B}, {T}, Sacrifice Memorial to Folly: Return target creature card from your graveyard to your hand.

Memorial to Genius enters the battlefield tapped. {T}: Add {U}. {4}{U}, {T}, Sacrifice Memorial to Genius: Draw two cards.

Myriad Landscape enters the battlefield tapped. {T}: Add {C}. {2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

{T}: Add {C}. {4}, {T}: Target creature can't be blocked this turn.

({T}: Add {U} or {B}.) Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

({T}: Add {B}.)

Temple of Deceit enters the battlefield tapped. When Temple of Deceit enters the battlefield, scry 1. {T}: Add {U} or {B}.

Thriving Isle enters the battlefield tapped. As Thriving Isle enters the battlefield, choose a color other than blue. {T}: Add {U} or one mana of the chosen color.

Spend only black mana on X. Consume Spirit deals X damage to any target and you gain X life.

Spend only black mana on X. Drain Life deals X damage to any target. You gain life equal to the damage dealt, but not more life than the player's life total before the damage was dealt, the planeswalker's loyalty before the damage was dealt, or the creature's toughness.

Each opponent loses X life. You gain life equal to the life lost this way.

Target opponent chooses X cards from their hand. Look at those cards. You may cast a spell from among them without paying its mana cost.

Return up to one target creature card from your graveyard to your hand. Venture into the dungeon. (Enter the first room or advance to the next room.)

Put target creature card from a graveyard onto the battlefield under your control with a corpse counter on it. If that creature would leave the battlefield, exile it instead of putting it anywhere else. You take the initiative. Escape—{3}{B}{B}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Each opponent reveals cards from the top of their library until they reveal X land cards, then puts all cards revealed this way into their graveyard. X can't be 0.

Choose two — • Target player loses X life. • Return target creature card with mana value X or less from your graveyard to the battlefield. • Target creature gets -X/-X until end of turn. • Up to X target creatures gain fear until end of turn. (They can't be blocked except by artifact creatures and/or black creatures.)

Return target creature card with mana value X or less from your graveyard to the battlefield.

{T}: Target creature with power 2 or less can't be blocked this turn.

Search your library for up to X cards, put those cards into your hand, then shuffle.

Whenever another creature you control dies, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.") Whenever you sacrifice a token, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Return X target creature cards from your graveyard to the battlefield. Miracle {X}{B}{B} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Whenever Hoard Robber deals combat damage to a player, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")