Arcane Investigator

Search the Room — {5}{U}: Roll a d20.
1—9 | Draw a card.
10—20 | Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any 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.

Hoarding Ogre

Whenever Hoarding Ogre attacks, roll a d20.
1—9 | Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
10—19 | Create two Treasure tokens.
20 | Create three Treasure tokens.

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.

Earth-Cult Elemental

Siege Monster — When Earth-Cult Elemental 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.

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.

Circuits Act

Roll three six-sided dice. For each different result, create a 1/1 white Clown Robot artifact creature token.

Brazen Dwarf

Whenever you roll one or more dice, Brazen Dwarf deals 1 damage to each opponent.

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.

Farideh's Fireball

Farideh's Fireball deals 5 damage to target creature or planeswalker. Roll a d20.
1—9 | Farideh's Fireball deals 2 damage to each player.
10—20 | Farideh's Fireball deals 2 damage to each opponent.

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.