Displacer Beast

When Displacer Beast enters, 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.

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.)

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Hama Pashar, Ruin Seeker

Room abilities of dungeons you own trigger an additional time.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Split the Party

Choose target player. Return half the creatures they control to their owner's hand, rounded up.

Oketra's Monument

White creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, create a 1/1 white Warrior creature token with vigilance.

Sol Ring

Fifty Feet of Rope

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.)

Island

Eccentric Apprentice

Flying
When Eccentric Apprentice enters, 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.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Scatter Ray

Counter target artifact or creature spell unless its controller pays {4}.

Plains

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Dungeon Delver

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

Shortcut Seeker

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

Yuan-Ti Malison

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.)

Sudden Insight

Draw a card for each different mana value among nonland cards in your graveyard.

Essence Scatter

Mind's Eye

Whenever an opponent draws a card, you may pay {1}. If you do, draw a card.

Dungeon Map

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

Secret Door

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

Trickster's Talisman

Invoke Duplicity — Equipped creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may sacrifice Trickster's Talisman. If you do, create a token that's a copy of this creature."
Equip {2}

Bar the Gate

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

Wizard's Spellbook

{T}: Exile target instant or sorcery card from a graveyard. Roll a d20. Activate only as a sorcery.
1—9 | Copy that card. You may cast the copy.
10—19 | Copy that card. You may cast the copy by paying {1} rather than paying its mana cost.
20 | Copy each card exiled with Wizard's Spellbook. You may cast any number of the copies without paying their mana costs.