Spiked Pit Trap

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

Obeka, Brute Chronologist

{T}: The player whose turn it is may end the turn. (Exile all spells and abilities from the stack. The player whose turn it is discards down to their maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

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.

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.

Goblin Tutor

Roll a six-sided die. If you roll a 1, Goblin Tutor has no effect. Otherwise, search your library for the indicated card, reveal it, put it into your hand, then shuffle.
2 — A card named Goblin Tutor
3 — An enchantment
4 — An artifact
5 — A creature
6 — An instant or sorcery

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}

Krark's Other Thumb

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

Hammer Jammer

As this creature enters, roll a six-sided die. This creature enters with a number of +1/+1 counters on it equal to the result.
Whenever you roll a die, remove all +1/+1 counters from this creature, then put a number of +1/+1 counters on it equal to the result.

Sundial of the Infinite

{1}, {T}: End the turn. Activate only during your turn. (Exile all spells and abilities from the stack. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

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.

Steel Squirrel

Whenever you roll a 5 or higher on a die, this creature gets +X/+X until end of turn, where X is the result.
{6}: Roll a six-sided die.

Jack-in-the-Mox

{T}: Roll a six-sided die. This ability has the indicated effect.
1 — Sacrifice this artifact and you lose 5 life.
2 — Add {W}.
3 — Add {U}.
4 — Add {B}.
5 — Add {R}.
6 — Add {G}.

Earth-Cult Elemental

Siege Monster — When this creature enters, roll a d20.
1—9 | Each player sacrifices a permanent of their choice.
10—19 | Each opponent sacrifices a permanent of their choice.
20 | Each opponent sacrifices two permanents of their choice.

Socketed Sprocketer

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

Hammer Helper

Gain control of target creature until end of turn. Untap that creature and roll a six-sided die. Until end of turn, it gains haste and gets +X/+0, where X is the result.

Ricochet

Whenever a player casts a spell that targets a single player, each player rolls a six-sided die. Change the target of that spell to the player with the lowest result. Reroll to break ties, if necessary.

Goblin Bookie

{R}, {T}: Reflip any coin or reroll any die. (Activate only any time it makes sense.)

Time Stop

End the turn. (Exile all spells and abilities, including this spell. The player whose turn it is discards down to their maximum hand size. Damage heals and "this turn" and "until end of turn" effects end.)

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.)

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}

Clam-I-Am

If you roll a 3 on a six-sided die, you may reroll that die.

Jumbo Imp

Flying
As this creature enters, roll a six-sided die. This creature enters with a number of +1/+1 counters on it equal to the result.
At the beginning of your upkeep, roll a six-sided die and put a number of +1/+1 counters on this creature equal to the result.
At the beginning of your end step, roll a six-sided die and remove a number of +1/+1 counters from this creature equal to the result.

Wall of Fortune

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

Treasure Chest

{4}, Sacrifice this artifact: 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.

Discontinuity

During your turn, this spell costs {2}{U}{U} less to cast.
End the turn. (Exile all spells and abilities from the stack, including this card. The player whose turn it is discards down to their maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Chaos Channeler

Wild Magic Surge — Whenever this creature attacks, roll a d20.
1—9 | Exile the top card of your library. You may play it this turn.
10—19 | Exile the top two cards of your library. You may play them this turn.
20 | Exile the top three cards of your library. You may play them this turn.