Deck of many things

In Dungeons & Dragons 5th Edition, The Deck of Many Things is a legendary wondrous item consisting of a box or pouch containing a deck of cards made of ivory or vellum (usually 13 or 22 cards).

Item Overview & Mechanics

 Rarity: Legendary wondrous item

 Activation: Before drawing a card, a character must declare how many cards they intend to draw and then draw them randomly.

 Core Rule: Any declared cards drawn beyond the stated number produce no effect. Each card’s magical effect takes place the instant it is drawn.

 Resetting: Unless the card drawn is the Fool or Jester (which disappear entirely), drawn cards vanish immediately and reappear in the deck, allowing the same card to potentially be drawn more than once.

Card Effects Breakdown (Full 22-Card Deck)

 Vizier: You gain the answer to a single question, solving a dilemma or gaining crucial insight.

 Sun: You gain 50,000 XP and a wondrous wondrous item appears in your hands.

 Moon: You are granted 1\text{d}3 castings of the Wish spell.

 Star: One ability score of your choice increases by 2 (can exceed the normal maximum of 20).

 Comet: If you single-handedly defeat the next hostile monster(s) you encounter, you gain enough XP to gain one level.

 The Fates: You can erase a single event from reality as if it never happened.

 Throne: You gain proficiency in Persuasion, double your proficiency bonus on checks with it, and gain ownership of a small keep currently overrun with monsters.

 Key: A rare or rarer magic weapon you are proficient with appears in your hands.

 Knight: You gain the service of a loyal 4th-level fighter who serves you until death.

 Gem: 25 pieces of jewelry (worth 2,000 gp each) or 50 gems (worth 1,000 gp each) appear at your feet.

 Jester: You gain 10,000 XP, or you may draw two additional cards beyond your declared amount.

 Fool: You lose 10,000 XP, discard this card, and must immediately draw one extra card.

 Rogue: An NPC of the DM's choice becomes secretly hostile and plots your downfall.

 Talons: Every magic item you are wearing or carrying is instantly disintegrated.

 Idiot: Your Intelligence permanently decreases by 1\text{d}4 + 1 (down to a minimum of 1), and you may draw one additional card.

 Euryale: A medusa-like curse permanently imposes a -2 penalty on all saving throws.

 Balance: Your alignment drastically shifts to its polar opposite (e.g., Lawful Good becomes Chaotic Evil).

 Ruins: All forms of personal wealth, real estate, and businesses you own (excluding carried gear) are lost.

 Flames: A powerful devil becomes your sworn enemy and seeks your ruin.

 Skull: You summon an Avatar of Death and must fight it alone; if anyone helps you, they summon their own Avatar.

 Donjon: You are instantly stripped of all gear and entrapped in an extradimensional sphere of suspended animation.

 The Void: Your soul is drawn from your body and imprisoned in an object guarded by powerful planar entities; your body remains comatose.