The Grand Calcutron

When The Grand Calcutron enters, each player's hand becomes a program (an ordered row of revealed cards).
Players can play only the first card of their program.
If a card would be put into a player's hand from anywhere, that player reveals it and places it anywhere within their program instead.
At the beginning of each player's end step, if that player's program has fewer than five cards, they draw cards equal to the difference.
The Grand Calcutron can be your commander.

Sandsteppe Citadel

This land enters tapped.
{T}: Add {W}, {B}, or {G}.

The Big Idea

{2}{B/R}{B/R}, {T}: Roll a six-sided die. Create a number of 1/1 red Brainiac creature tokens equal to the result.
Tap three untapped Brainiacs you control: The next time you would roll a six-sided die, instead roll two six-sided dice and use the total of those results.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Main Event Horizon

As an additional cost to cast this spell, choose A through M or N through Z.
Destroy each creature whose name begins with a letter in the chosen range.

Bag of Tricks

{4}{G}, {T}: Roll a d8. Reveal cards from the top of your library until you reveal a creature card with mana value equal to the result. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Prismatic Wardrobe

Destroy target nonartifact, nonland permanent that doesn't share a color with clothing worn by its controller.

Crumbling Necropolis

This land enters tapped.
{T}: Add {U}, {B}, or {R}.

Animate Library

Enchant your library
Enchanted library is an artifact creature on the battlefield with power and toughness each equal to the number of cards in it. It's still a library.
If enchanted library would leave the battlefield, exile this Aura instead.

Feywild Trickster

Whenever you roll one or more dice, create a 1/1 blue Faerie Dragon creature token with flying.

Ol' Buzzbark

When Ol' Buzzbark enters, roll X six-sided dice onto the battlefield from a height of at least X inches. For each die, put a number of +1/+1 counters equal to the result on each creature you control that die is touching. For each die, Ol' Buzzbark deals damage equal to the result to each creature an opponent controls that die is touching.

Arcane Sanctum

This land enters tapped.
{T}: Add {W}, {U}, or {B}.

Mobile Clone

Using a mobile device, take a picture of target creature. That device enters as a token that's a photocopy of the pictured creature. (Photocopies include Auras, Equipment, counters, and stickers in the shot. Don't touch other people's phones without permission and be careful if you do.)

Gruul Guildgate

This land enters tapped.
{T}: Add {R} or {G}.

Knife and Death

Just a second (As long as this spell is on the stack, players can't move permanents.)
One at a time, throw ten cards you own from outside the game onto the playing area from a distance of at least three feet (about one meter). For each of those cards, Knife and Death deals 1 damage to each creature or planeswalker you don't control that card is touching. You gain life equal to the damage dealt this way.

Minds Aglow

Join forces — Starting with you, each player may pay any amount of mana. Each player draws X cards, where X is the total amount of mana paid this way.

Mystic Monastery

This land enters tapped.
{T}: Add {U}, {R}, or {W}.

Earl of Squirrel

Squirrellink (Damage dealt by this creature also causes you to create that many 1/1 green Squirrel creature tokens.)
Creature tokens you control are Squirrels in addition to their other creature types.
Other Squirrels you control get +1/+1.

Transguild Promenade

This land enters tapped.
When this land enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Sword of Dungeons & Dragons

Equipped creature gets +2/+2 and has protection from Rogues and from Clerics.
Whenever equipped creature deals combat damage to a player, create a 4/4 gold Dragon creature token with flying and roll a d20 (a twenty-sided die). If you roll a 20, repeat this process.
Equip {2}

Krark's Other Thumb

If you would roll a die, instead roll two of those dice and ignore one of those results.

As Luck Would Have It

Hexproof
Whenever you roll a die, put a number of luck counters on this enchantment equal to the result. Then if there are 100 or more luck counters on this enchantment, you win the game. (Count both rolls if you reroll a die.)

Rupture Spire

Archway Commons

Strategy, Schmategy

Roll a six-sided die. Strategy, Schmategy has the indicated effect.
1 — Do nothing.
2 — Destroy all artifacts.
3 — Destroy all lands.
4 — Strategy, Schmategy deals 3 damage to each creature and each player.
5 — Each player discards their hand and draws seven cards.
6 — Repeat this process two more times.

Seaside Citadel

This land enters tapped.
{T}: Add {G}, {W}, or {U}.

Selfie Preservation

Search your library for a basic land card and reveal it. If there's a tree in its art, put it onto the battlefield tapped. Otherwise, put it into your hand. Then shuffle.

Urza's Science Fair Project

{2}: Roll a six-sided die. This creature gets the indicated result.
1 — It gets -2/-2 until end of turn.
2 — Prevent all combat damage it would deal this turn.
3 — It gains vigilance until end of turn.
4 — It gains first strike until end of turn.
5 — It gains flying until end of turn.
6 — It gets +2/+2 until end of turn.

Selesnya Guildgate

This land enters tapped.
{T}: Add {G} or {W}.

Rings a Bell

As this enchantment enters, choose a word with four or more letters.
After you say the chosen word for the first time each turn, an opponent may ring or imitate a bell within five seconds. When no opponent does, draw a card.

Forest

Urza's Fun House

{T}: Add {C}.
{T}: Add {∞}. Activate only once and only if you control an Urza's Mine, an Urza's Power-Plant, and an Urza's Tower.
{7}, {T}: Head to AskUrza.com and click Urza's Fun House.

Spelling Bee

Flying, deathtouch
Whenever this creature deals combat damage to a player, that player looks at the top card of your library and chooses a word on that card. You spell that word. If you spell it correctly, draw a card. Otherwise, scry 1.

Checks and Balances

Cast this spell only if there are three or more players in the game.
Whenever a player casts a spell, each of that player's opponents may discard a card. If they do, counter that spell.

Orzhov Guildgate

This land enters tapped.
{T}: Add {W} or {B}.

Public Thoroughfare

This land enters tapped.
When this land enters, sacrifice it unless you tap an untapped artifact or land you control.
{T}: Add one mana of any color.

Clocknapper

When this creature enters, choose beginning phase, first main phase, combat phase, postcombat main phase, or ending phase. Steal that phase from target player during their next turn. (That phase occurs as though it's your turn instead.)

Form of the Approach of the Second Sun

When this enchantment enters, you gain 7 life. You become a card until you leave your library or that library is shuffled. Put yourself seventh from the top, balancing the cards on top of you on your head.
When you draw yourself, you win the game.
When one or more cards fall off your head, exile them and all cards on your head, then sacrifice this enchantment.

Night Shift of the Living Dead

After you roll a die, you may pay 1 life. If you do, increase or decrease the result by 1. Do this only once each turn.
Whenever you roll a 6, create a 2/2 black Zombie Employee creature token.

Exit Through the Grift Shop

Yell "Who wants a souvenir?" and announce the name of a nonland card in your graveyard. Each player in an Un-game who can hear you may bid life. You start the bidding at 0. The high bidder loses life equal to the high bid. They copy the card and may cast the copy without paying its mana cost. If you didn't win the bid, you gain life equal to the high bid and create that many Treasure tokens.

Jermane, Pride of the Circus

{G}, {T}: Put two +1/+1 counters on target creature with four or more legs.
{1}{G}{G}, {T}: Until end of turn, all creatures able to block target creature with four or more legs do so.

Nomad Outpost

This land enters tapped.
{T}: Add {R}, {W}, or {B}.

Ignacio of Myra's Marvels

As Ignacio of Myra's Marvels enters, choose armor, blood, book, bottle, fang, fire, scroll, spear, sword, or water.
Whenever you cast a spell with the chosen object in its art, create two Treasure tokens.
Partner (You can have two commanders if both have partner.)

Frontier Bivouac

This land enters tapped.
{T}: Add {G}, {U}, or {R}.

Modular Monstrosity

Whenever an opponent casts a spell, you have five seconds to choose a keyword you haven't chosen for a card named Modular Monstrosity today that's been printed on a creature card. If you do, this creature gains that ability. Otherwise, this creature loses all keyword abilities.

Wall of Reverence

Defender, flying
At the beginning of your end step, you may gain life equal to the power of target creature you control.

Plains

Dimir Guildgate

This land enters tapped.
{T}: Add {U} or {B}.

Door to Nothingness

This artifact enters tapped.
{W}{W}{U}{U}{B}{B}{R}{R}{G}{G}, {T}, Sacrifice this artifact: Target player loses the game.

Proteus Staff

{2}{U}, {T}: Put target creature on the bottom of its owner's library. That creature's controller reveals cards from the top of their library until they reveal a creature card. The player puts that card onto the battlefield and the rest on the bottom of their library in any order. Activate only as a sorcery.

Rakdos Guildgate

This land enters tapped.
{T}: Add {B} or {R}.

Number Crunch

Return target permanent to its owner's hand.
Gotcha — If an opponent says a number, you may say "Gotcha!" When you do, return this card from your graveyard to your hand.

Summon the Pack

Open a sealed Magic booster pack, reveal the cards, and put all creature cards revealed this way onto the battlefield under your control. They're Zombies in addition to their other types. (Remove those cards from your deck before beginning a new game.)

Swamp

As long as X is in X's owner's opponent's hand, X's owner may cast X and activate X's abilities. That opponent can't cast X and plays with their hand revealed.
{U}{B}, {T}: Put X into target opponent's hand.
{3}{U}{B}: You may play a land or cast a spell from the hand X is in. If you cast a spell this way, you cast it without paying its mana cost.

Urza, Academy Headmaster

+1: Head to AskUrza.com and click +1.
−1: Head to AskUrza.com and click -1.
−6: Head to AskUrza.com and click -6.

Primeval Spawn

If this creature would enter and it wasn't cast or no mana was spent to cast it, exile it instead.
Vigilance, trample, lifelink
When this creature leaves the battlefield, exile the top ten cards of your library. You may cast any number of spells with total mana value 10 or less from among them without paying their mana costs.

Opulent Palace

This land enters tapped.
{T}: Add {B}, {G}, or {U}.

Savage Lands

This land enters tapped.
{T}: Add {B}, {R}, or {G}.

Pixie Guide

Flying
Grant an Advantage — If you would roll one or more dice, instead roll that many dice plus one and ignore the lowest roll.

Tug of War

Players play a subgame starting at 5 life and with up to three permanent cards with different names from their main-game library on the battlefield. As the subgame ends, the winner chooses one of the cards they put onto the battlefield as the subgame began and puts it onto the battlefield rather than shuffling it into their library.

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 this artifact. You may cast any number of the copies without paying their mana costs.

Vrondiss, Rage of Ancients

Enrage — Whenever Vrondiss is dealt damage, you may create a 5/4 red and green Dragon Spirit creature token with "When this token deals damage, sacrifice it."
Whenever you roll one or more dice, you may have Vrondiss deal 1 damage to itself.

Command Tower

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

Island

Boros Guildgate

This land enters tapped.
{T}: Add {R} or {W}.

Do-It-Yourself Seraph

Flying
Whenever this creature attacks, you may search your library for an artifact card, exile it, then shuffle.
This creature has the text box of each card exiled with this creature in addition to its own.

Golgari Guildgate

This land enters tapped.
{T}: Add {B} or {G}.

Killer Cosplay

Whenever this Equipment becomes attached to a creature, choose a creature card name with an identical mana cost. That creature becomes a copy of the card with the chosen name until this Equipment becomes unattached from it.
Equip {3}

Oddly Uneven

Choose one —
• Destroy each creature with an odd number of words in its name. (Hyphenated words are one word.)
• Destroy each creature with an even number of words in its name.

Gerrymandering

Exile all lands. Give each player a number of those cards chosen at random equal to the number of those cards the player controlled. Each player returns those cards to the battlefield under their control.

Izzet Guildgate

This land enters tapped.
{T}: Add {U} or {R}.

Jungle Shrine

This land enters tapped.
{T}: Add {R}, {G}, or {W}.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Infinity Elemental

Captain Rex Nebula

At the beginning of combat on your turn, choose target nonland permanent you control. Until end of turn, it becomes a Vehicle artifact with base power and toughness each equal to its mana value, and it gains crew 2 and "Crash Land — Whenever this Vehicle deals damage, roll a six-sided die. If the result is equal to this Vehicle's mana value, sacrifice this Vehicle, then it deals that much damage to any target."

Over My Dead Bodies

Creature cards in graveyards can attack and block as though they were on the battlefield, can block or be blocked only by creature cards in graveyards, are Zombies in addition to their other types, and have undeathtouch. (If they would deal damage to a creature card, exile that creature card instead.)
Creature cards in your graveyard have haste.

Gateway Plaza

Land Aid '04

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. If you sang a song the whole time you were searching and shuffling, you may untap that land.

Nearby Planet

Rangeling (This card is every land type, including Plains, Island, Swamp, Mountain, Forest, Desert, Gate, Lair, Locus, and all those Urza's ones.)
This land enters tapped.
When this land enters, sacrifice it unless you pay {1}.

Centaur of Attention

When this creature enters, roll five six-sided dice and store those results on it.
At the beginning of combat on your turn, you may reroll any number of this creature's stored results.
This creature gets +X/+X, where X is the greatest number of stored results on it of the same value.

Howling Mine

At the beginning of each player's draw step, if this artifact is untapped, that player draws an additional card.

How Is This a Par Three?!

Whenever you cast a spell, you may have target player mill X cards, where X is the number of words in that spell's name.

Touch and Go

Destroy target land.
Gotcha — If an opponent touches their face, you may say "Gotcha!" When you do, return this card from your graveyard to your hand.

Cramped Bunker

At the beginning of each opponent's upkeep, that player moves a permanent they control to touch this enchantment and no other permanents. If the player can't, destroy each permanent they control that isn't touching this enchantment, then sacrifice it.

Mountain

Park Map

{1}, Sacrifice this artifact: Search your library for a land card that doesn't have the same art as a permanent you control, reveal it, put it into your hand, then shuffle.

Split Screen

When this artifact enters, shuffle your library and deal it into four libraries. If anything refers to your library, choose one of your libraries for it.
Play with your libraries' top cards revealed.
When this artifact leaves the battlefield, shuffle your libraries together.

Vedalken Squirrel-Whacker

As this creature enters, roll a six-sided die twice. Its base power becomes the first result and its base toughness becomes the second result.
If you would roll one or more six-sided dice, instead roll them and you may exchange one result with this creature's base power or base toughness.

Alexander Clamilton

Whenever you cast a wordy spell, scry 2. (A spell is wordy if it has four or more lines of rules text.)
{1}{R}, {T}: Choose target creature you don't control. Reveal the top card of your library. Alexander Clamilton gets +X/+0 until end of turn, where X is the number of lines of rules text of the revealed card. Alexander Clamilton fights that creature.

Trade Secrets

Target opponent draws two cards, then you draw up to four cards. That opponent may repeat this process as many times as they choose.

Villainous Wealth

Target opponent exiles the top X cards of their library. You may cast any number of spells with mana value X or less from among them without paying their mana costs.

Pygmy Giant

{R}, {T}, Sacrifice a creature: This creature deals X damage to target creature, where X is a number in the sacrificed creature's text box.

Graveyard Busybody

All graveyards are also your graveyards.
Graveyard Busybody's power and toughness are each equal to the number of cards with flavor text in your graveyards.

Hydradoodle

As this creature enters, roll X six-sided dice. This creature enters with a number of +1/+1 counters on it equal to the total of those results.
Reach, trample