Deck thinning is the term for cards that are used to reduce the size of your deck to increase the chances of drawing whatever particular card you may need. Single-use cards that only draw one card, such as "Jar of Greed" or "Upstart Goblin" have little use other than to thin the deck. Deck thinning may be achieved by searching for specific cards from the deck, increasing the number of cards you draw in a turn or simply by getting rid of cards in your Deck such as with "Foolish Burial" or "Painful Choice". Deck thinning is generally not considered useful in large decks since it is simpler to just make a deck with the minimum of 40 cards and have the deck-thinners among those 40 cards.
Deck thinning is the preferred method of winning in a "Forbidden One" Deck.
Useful Deck-thinning cards
Cards that allow you to draw extra cards will not be listed here unless they exist only to thin the deck such as "Jar of Greed". Self-milling cards such as "Destruction of Destiny" or "Needlebug Nest" will not be listed here as those cards indiscriminately send cards to the Graveyard, defeating the purpose of attempting to narrow the possibilities for what you might wish to draw.
- Royal Magic Library
- Thunder Dragon
- Volcanic Shell
- Green Gadget, Yellow Gadget and Red Gadget
- Toon Table of Contents x3 + "Toon" card.
- Gather Your Mind
- Jar of Greed
- Upstart Goblin
- Good Goblin Housekeeping
- Reckless Greed
- Guard Penalty
- Magical Hats
- Foolish Burial
- Painful Choice (Traditional)
- Future Fusion
- One Day of Peace
- Legacy of Yata-Garasu or "Jar of Greed"
- Golden Bamboo Sword + Broken Bamboo Sword
There are many monsters that have the ability to Special Summon copies of themselves with little to no assistance from other cards. Most of these can provide a sturdy defense and all are considered to be useful Deck thinners: