Whenever you cast a permanent spell with a mana cost that contains , double the value of X.

Whenever you cast an instant or sorcery spell or activate an ability, if that spell's mana cost or that ability's activation cost contains , copy that spell or ability. You may choose new targets for the copy.

Return target creature card from your graveyard to the battlefield with a lifelink counter on it.

Unbreathing Horde enters with a +1/+1 counter on it for each other Zombie you control and each Zombie card in your graveyard.

If Unbreathing Horde would be dealt damage, prevent that damage and remove a +1/+1 counter from it.

Target player discards two cards.

Cycling (, Discard this card: Draw a card.)

Search your library for up to X creature cards with different names that each have mana value X, reveal them, put them into your hand, then shuffle.

Target creature gets +3/+0 and gains haste until end of turn.

Uncharted Haven enters tapped. As it enters, choose a color.

: Add one mana of the chosen color.

Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)

If a creature you control with a +1/+1 counter on it would deal damage to a permanent or player, it deals double that damage instead.

Prevent all damage that would be dealt to Uncle Istvan by creatures.

Flash (You may cast this spell any time you could cast an instant.)

Enchant creature

Enchanted creature gets +2/+2 and attacks each combat if able.

Target creature gets +3/+3 and gains flying until end of turn.

Whenever a Zombie you control enters, you may pay . If you do, return Unconventional Tactics from your graveyard to your hand.

Other blue creatures you control have "Whenever this creature becomes tapped, draw a card, then discard a card."

Other artifact creatures you control get +1/+1.

: Until end of turn, target creature you control becomes a blue artifact in addition to its other colors and types. Activate only as a sorcery. ( can be paid with either or 2 life.)

If a Zombie you control would deal combat damage to a player, instead that player mills that many cards.

Whenever a creature card is put into an opponent's graveyard from their library, exile that card and create a 2/2 black Zombie creature token.

When Undead Butler enters, mill three cards. (Put the top three cards of your library into your graveyard.)

When Undead Butler dies, you may exile it. When you do, return target creature card from your graveyard to your hand.

, Discard a card: Return Undead Gladiator from your graveyard to your hand. Activate only during your upkeep.

Cycling (, Discard this card: Draw a card.)

, : Exile target Skeleton, Vampire, or Zombie.

Zombie spells you cast cost less to cast.

Zombie creatures you control get +2/+1.

When Undercellar Myconid enters or dies, create a 1/1 green Saproling creature token.

: Add one mana of any color.

You can't enter this dungeon unless you "venture into Undercity."

Secret Entrance — Search your library for a basic land card, reveal it, put it into your hand, then shuffle. (Forge, Lost Well)

Forge — Put two +1/+1 counters on target creature. (Trap, Arena)

Lost Well — Scry 2. (Arena, Stash)

Trap — Target player loses 5 life. (Archives)

Arena — Goad target creature. (Archives, Catacombs)

Stash — Create a Treasure token. (Catacombs)

Archives — Draw a card. (Throne of the Dead Three)

Catacombs — Create a 4/1 black Skeleton creature token with menace. (Throne of the Dead Three)

Throne of the Dead Three — Reveal the top ten cards of your library. Put a creature card from among them onto the battlefield with three +1/+1 counters on it. It gains hexproof until your next turn. Then shuffle.

, Sacrifice a creature: Target player reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Target player loses 1 life, discards a card, then sacrifices a permanent.

Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

When Undercity Scavenger enters, you may sacrifice another creature. If you do, put two +1/+1 counters on Undercity Scavenger, then scry 2.

(: Add or .)

Undercity Sewers enters tapped.

When Undercity Sewers enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)

: Regenerate Undercity Troll. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Creatures you control gain deathtouch until end of turn. Then target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Level up (: Put a level counter on this. Level up only as a sorcery.)

: Add .

LEVEL 1-7

: Add , , , or .

LEVEL 8+

: Add , , , or . Scry 1.

Whenever Undercover Crocodelf deals combat damage to a player, investigate. (Create a Clue token. It's an artifact with ", Sacrifice this artifact: Draw a card.")

Disguise (You may cast this card face down for as a 2/2 creature with ward . Turn it face up any time for its disguise cost.)

Deathtouch

Menace (This creature can't be blocked except by two or more creatures.)

When Underdark Explorer enters, you take the initiative.

: Add .

: Add one mana of any color. Spend this mana only to pay Un-costs.

: Add .

: Add or . Underground River deals 1 damage to you.

As an additional cost to cast this spell, you may pay .

Prevent all combat damage that would be dealt this turn. If this spell's additional cost was paid, this effect doesn't affect combat damage that would be dealt by red creatures.

At the beginning of your upkeep, return target land card from your graveyard to the battlefield tapped.

Undergrowth Stadium enters tapped unless you have two or more opponents.

: Add or .

Counter target spell. Its controller loses 3 life.

If you would draw a card, instead look at the top three cards of your library, then put one into your hand and the rest into your graveyard.

Pay 4 life: Underrealm Lich gains indestructible until end of turn. Tap it.

Choose target spell. If it's a creature spell, it perpetually gets -2/-0. Counter that spell unless its controller pays .

Creatures with islandwalk can be blocked as though they didn't have islandwalk.

Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)

At the beginning of the end step, sacrifice Underworld Breach.

Underworld Charger can't block.

Escape—, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Underworld Charger escapes with two +1/+1 counters on it.

Enchant land

Enchanted land has ", Pay 1 life: Draw a card."

Underworld Fires deals 1 damage to each creature and each planeswalker. If a permanent dealt damage this way would die this turn, exile it instead.

Underworld Rage-Hound attacks each combat if able.

Escape—, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Underworld Rage-Hound escapes with a +1/+1 counter on it.

: Add one mana of any color. During your next untap step, as you untap your permanents, return Undiscovered Paradise to its owner's hand.

When Undying Beast dies, put it on top of its owner's library.

Exile cards from the top of your library until you exile a nonland card. Undying Flames deals damage to any target equal to that card's mana value.

Epic (For the rest of the game, you can't cast spells. At the beginning of each of your upkeeps, copy this spell except for its epic ability. You may choose a new target for the copy.)

Enchant creature

Enchanted creature gets +2/+2 and can't block.

When Undying Rage is put into a graveyard from the battlefield, return Undying Rage to its owner's hand.

Up to three target creatures can't block this turn.

Flying

Sphinx spells you cast cost less to cast.

Whenever Unesh, Criosphinx Sovereign or another Sphinx you control enters, reveal the top four cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.