Proper Laboratory Attire

Equipped creature gets +2/+1 and has protection from die rolls. (Nothing that lets a player roll a die can block, target, deal damage to, or attach to equipped creature.)
Equip {2}

Pippa, Duchess of Dice

{2}{G}, {T}: Roll a six-sided die. It becomes a green Die creature token with power and toughness each equal to its result.
{2}{U}, {T}: Reroll any die. (Activate only any time it makes sense.)

Form of the Squirrel

As Form of the Squirrel enters, create a 1/1 green Squirrel creature token. You lose the game when that creature leaves the battlefield.
Creatures can't attack you.
You have shroud.
You can't cast spells.

Netherese Puzzle-Ward

Focus Beam — At the beginning of your upkeep, roll a d4. Scry X, where X is the result.
Perfect Illumination — Whenever you roll a die's highest natural result, draw a card.

Diviner's Portent

Roll a d20 and add the number of cards in your hand.
1—14 | Draw X cards.
15+ | Scry X, then draw X cards.

Sword of Hours

Whenever equipped creature attacks, put a +1/+1 counter on it.
Whenever equipped creature deals combat damage, roll a d12. If the result is greater than the damage dealt or the result is 12, double the number of +1/+1 counters on that creature.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

As Luck Would Have It

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

Cone of Cold

Roll a d20.
1—9 | Tap all creatures your opponents control.
10—19 | Tap all creatures your opponents control. Those creatures don't untap during their controllers' next untap steps.
20 | Tap all creatures your opponents control. Those creatures don't untap during their controllers' next untap steps. Until your next turn, creatures your opponents control enter tapped.

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}

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.

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.

Mad Science Fair Project

{T}: Roll a six-sided die. On a 3 or lower, target player adds {C}. Otherwise, that player adds one mana of any color they choose.

Acorn Catapult

{1}, {T}: Acorn Catapult deals 1 damage to any target. That permanent's controller or that player creates a 1/1 green Squirrel creature token.

Boing!

Return target creature to its owner's hand, then roll a six-sided die. If the result is 3 or less, scry a number of cards equal to the result.

Exchange of Words

When Exchange of Words enters, choose two target creatures. For as long as Exchange of Words remains on the battlefield, exchange the text boxes of those creatures.

Socketed Sprocketer

{T}: Uninstall all results from Socketed Sprocketer, then roll a six-sided die. Install the result on Socketed Sprocketer. (Put the die on this card.)
You may uninstall a result from Socketed Sprocketer to use it for a die you rolled.
Uninstall a 6 from Socketed Sprocketer: Draw a card.

Lobe Lobber

Equipped creature has "{T}: This creature deals 1 damage to target player or planeswalker. Roll a six-sided die. On a 5 or higher, untap it."
Equip {2}

Strength-Testing Hammer

Whenever equipped creature attacks, roll a six-sided die. That creature gets +X/+0 until end of turn, where X is the result. Then if it has the greatest power or is tied for greatest power among creatures on the battlefield, draw a card.
Equip {3}

Resolute Veggiesaur

Trample
Whenever you roll your third die each turn, put a +1/+1 counter on Resolute Veggiesaur.

Vedalken Squirrel-Whacker

As Vedalken Squirrel-Whacker 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 Vedalken Squirrel-Whacker's base power or base toughness.

Elvish Impersonators

As Elvish Impersonators enters, roll a six-sided die twice. Its base power becomes the first result and its base toughness becomes the second result.

Bamboozling Beeble

Protection from Robots
{1}, {T}: The next time target player would roll one or more dice this turn, instead they roll that many dice plus one and you choose one of those rolls to ignore.

Scion of Stygia

Flash
Cone of Cold — When Scion of Stygia enters, choose target creature an opponent controls, then roll a d20.
1—9 | Tap that creature.
10—20 | Tap that creature. It doesn't untap during its controller's next untap step.

Feywild Trickster

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

Monitor Monitor

When Monitor Monitor enters, open an Attraction. (Put the top card of your Attraction deck onto the battlefield.)
Once each turn, you may pay {1} to reroll one or more dice you rolled.

Command Performance

Choose two —
• Open an Attraction. (Put the top card of your Attraction deck onto the battlefield.)
• Roll to visit your Attractions.
• You get {TK}{TK}.
• You may put a sticker on a nonland permanent you own.

Journey to the Lost City

At the beginning of your upkeep, exile the top four cards of your library, then roll a d20.
1—9 | You may put a land card from among those cards onto the battlefield.
10—19 | Create a 2/2 green Wolf creature token, then put a +1/+1 counter on it for each creature card among those cards.
20 | Put all permanent cards exiled with Journey to the Lost City onto the battlefield, then sacrifice it.

Druid of the Emerald Grove

When Druid of the Emerald Grove enters, search your library for up to two basic land cards and reveal them, then roll a d20.
9 or less | Put those cards into your hand, then shuffle.
10—19 | Put one of those cards onto the battlefield tapped and the other into your hand, then shuffle.
20+ | Put those cards onto the battlefield tapped, then shuffle.

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.

Contact Other Plane

Roll a d20.
1—9 | Draw two cards.
10—19 | Scry 2, then draw two cards.
20 | Scry 3, then draw three cards.

Ichor Elixir

If you would roll one or more planar dice, instead roll that many planar dice plus one and ignore one.
{T}: Add {C}{C}.

The Deck of Many Things

{2}, {T}: Roll a d20 and subtract the number of cards in your hand. If the result is 0 or less, discard your hand.
1—9 | Return a card at random from your graveyard to your hand.
10—19 | Draw two cards.
20 | Put a creature card from any graveyard onto the battlefield under your control. When that creature dies, its owner loses the game.

Ancient Silver Dragon

Flying
Whenever Ancient Silver Dragon deals combat damage to a player, roll a d20. Draw cards equal to the result. You have no maximum hand size for the rest of the game.

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.

Ancient Bronze Dragon

Flying
Whenever Ancient Bronze Dragon deals combat damage to a player, roll a d20. When you do, put X +1/+1 counters on each of up to two target creatures, where X is the result.

Component Pouch

{T}, Remove a component counter from Component Pouch: Add two mana of different colors.
{T}: Roll a d20.
1—9 | Put a component counter on Component Pouch.
10—20 | Put two component counters on Component Pouch.

Centaur of Attention

When Centaur of Attention 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 Centaur of Attention's stored results.
Centaur of Attention gets +X/+X, where X is the greatest number of stored results on it of the same value.

Spiked Pit Trap

Flash
{5}, {T}, Sacrifice Spiked Pit Trap: Choose target creature, then roll a d20.
1—9 | Spiked Pit Trap deals 5 damage to that creature.
10—20 | Spiked Pit Trap deals 5 damage to that creature. Create a Treasure token.

Wall of Fortune

Defender
You may tap an untapped Wall you control to have any player reroll a die that player rolled.

Time Out

Roll a six-sided die. Put target nonland permanent into its owner's library just beneath the top X cards of that library, where X is the result.

Fowl Play

Enchant creature
Enchanted creature loses all abilities and is a Bird creature with base power and toughness 1/1.

Sylvan Shepherd

Vigilance
Whenever Sylvan Shepherd attacks, roll a d20.
1—9 | You gain 1 life.
10—19 | You gain 2 life.
20 | You gain 5 life.

Coming Attraction

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Open an Attraction. (Put the top card of your Attraction deck onto the battlefield.)

Chicken à la King

Whenever a 6 is rolled on a six-sided die, put a +1/+1 counter on each Bird. (You may roll dice only when instructed to.)
Tap an untapped Bird you control: Roll a six-sided die. (Like now.)

Song of Inspiration

Choose up to two target permanent cards in your graveyard. Roll a d20 and add the total mana value of those cards.
1—14 | Return those cards to your hand.
15+ | Return those cards to your hand. You gain life equal to their total mana value.

Atomwheel Acrobats

Whenever you roll a 1 or 2, put that many +1/+1 counters on Atomwheel Acrobats.
{2}{G}: Roll a six-sided die.

Simon, Wild Magic Sorcerer

Whenever you cast an instant or sorcery spell with mana value 3 or greater, roll a d20.
1-9 | Each player draws a card.
10-19 | You draw a card.
20 | Copy that spell. You may choose new targets for the copy.

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.

Power of Persuasion

Choose target creature an opponent controls, then roll a d20.
1—9 | Return it to its owner's hand.
10—19 | Its owner puts it on the top or bottom of their library.
20 | Gain control of it until the end of your next turn.

Overwhelming Encounter

Creatures you control gain vigilance and trample until end of turn. Roll a d20.
1—9 | Creatures you control get +2/+2 until end of turn.
10—19 | Put two +1/+1 counters on each creature you control.
20 | Put four +1/+1 counters on each creature you control.

Very Cryptic Command

Choose two —
• Counter target black-bordered spell.
• Return target creature to its owner's hand.
• Untap each permanent you control with a watermark.
• Roll two six-sided dice. Target player mills X cards, where X is the total of those results.

Hydradoodle

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

Willing Test Subject

Reach
Whenever you roll a 4 or higher on a die, put a +1/+1 counter on Willing Test Subject.
{6}: Roll a six-sided die.

Chittering Doom

Whenever you roll a 4 or higher on a die, create a 1/1 green Squirrel creature token.

Growth Spurt

Roll a six-sided die. Target creature gets +X/+X until end of turn, where X is the result.

Vexing Puzzlebox

Whenever you roll one or more dice, put a number of charge counters on Vexing Puzzlebox equal to the result.
{T}: Add one mana of any color. Roll a d20.
{T}, Remove 100 charge counters from Vexing Puzzlebox: Search your library for an artifact card, put that card onto the battlefield, then shuffle.

Krark's Other Thumb

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

Pair o' Dice Lost

Roll two six-sided dice. Return any number of cards with total mana value X or less from your graveyard to your hand, where X is the total of those results. Exile Pair o' Dice Lost.