This deck of playing cards has a charred purple color almost as if it was put through a dying process. The stranger part of them though is that they all have 1 or more holes punched straight through them.
After studying the cards for a long or short rest you figure out that the holes correspond to how strong the magic of the card is. Each numbered card has a number of holes punched in it equal to half its value rounded down. Face cards all have 5 holes, but aces are different. They only have a single hole, and its much larger than any of the other cards’ holes.
As an action you may draw a card and choose to either activate it or return it to the bottom of the deck. If you activate it you may create a number of 10 foot wide 10 foot deep extradimensional holes, within 60 feet of you, equal to to the number of holes on the card. If you so choose you can make any pit you have already created 10 feet deeper instead of creating a new pit.
The exception to the rules are the aces. When you activate an ace you may only create a single hole, but the hole is 20 feet wide and 2d4 x 10 feet deep. These holes can only be made deeper with another ace card.
Properties of the holes
The space within these holes exist on separate demi-planes so they do not affect structural integrity or create open passages.
Each minute after a pit is created it gets 10 feet shorter until it doesn’t exist at all or until you activate the card again. If you activate the card again the extradimensional space collapses and everything within the hole is rapidly expelled through the hole(s) in the card. Creatures that are expelled in this way take 2d10 bludgeoning damage.
Once a card is used to create a hole any holes punched in it disappear and it becomes a mundane, albeit still purple, playing card.