A deck of many things is one of the most powerful magical items in the Advanced Dungeons and Dragons game. It is also one of the most deadly items you can encounter.
The deck is usually found in a leather pouch or a small wooden box. Each deck has either 15 or 22 cards featuring various rune symbols. Drawing a card instantly activates that card's magic. You can draw as many cards at a time as you want, but you must announce the number beforehand, the DMG implies that the deck disappears after a player draws his cards.
- Sun: A miscellaneous magical item appears and the player is blessed with 50,000 XP. That is enough experience to make some characters gain as many as six levels.
- Moon: The player is granted between one and four wishes, which must be used quickly.
- Star: On drawing the star card the player will have his prime requisite raised by two points. For example a fighter with a 14 strength would be given a 16 strength. While a wizard with an 18 intelligence would be granted a 20 intelligence.
- Comet: Nothing seems to happen upon drawing this card. But the character will gain one level if she defeats the next monster she meets.
- Throne: The character is blessed with a charisma of 18 and a small castle. I have no idea how you are supposed to know where your new castle is.
- Key: When this key card is drawn a magical weapon and a treasure map appear at the player's feet. The weapon will always be of a type that the character is proficient in.
- Knight: This card makes people! Well, actually, just one person—a 4th level warrior will appear and serve the player until death.
- Gem: Gain your choice of 20 items of jewelry or 50 valuable gems.
- Void: Drawing the void card pulls the character's soul to another plane, making him a complete automaton. Not even a wish will bring the character back. Draw no more cards.
- Flames: You gain a powerful enemy in the form of an outer planar creature that will not rest until one member of your party has been destroyed. The exact type of creature is up to the dungeon master.
- Skull: Death himself appears to battle the character. He always strikes first and never misses. The player must fight death alone. Anyone attempting to help will gain a death of their own to battle.
- Talons: All of your magical items disappear, including the deck. Not even a wish can retrieve them.
- Ruin: You are immediately impoverished. All money, gems, art objects, jewelry, trade goods, land, and buildings that are owned by the character vanish forever.
- Euryale: Gain a permanent -3 penalty on your savings throw against petrification. This cannot be removed in any way.
- Rogue: Nothing appears to happen when this card is drawn. But one of the character's henchmen, or other trusted friends, has completely turned against him. They will wait for an opportune time to show their betrayal.
- Balance: Your alignment is instantly and permanently changed to one that has nothing in common with your previous one. For example, Lawful Good characters may change to Chaotic Neutral or any other alignment that is neither lawful nor good. Draw no more cards.
- Jester: Gain 10,000 XP or two more draws from the deck (take the XP).
- Fool: Lose 10,000 XP and draw another card. This second card must be drawn; it is not an option.
- Vizier: The character can ask one question of the gods. This need not be done immediately. There is no guarantee that the player will understand the answer, however.
- Idiot: Permanently lose from 1 to 4 intelligence points and draw another card if you like. Any player who is role-playing his character correctly will draw another card, because after all you just became too stupid to know better.
- Fates: You may avoid any situation that you wish, but only one time. This even works for things that happen instantly. You can save this blessing until it is needed.
- Donjon: The character and his equipment vanish. The player has been imprisoned in some way. What happened to his items is up to the dungeon master.
Based on material from the Dungeon Masters Guide.