Mill Deck

A Mill Deck centers around getting through the contents of your opponent's Deck very rapidly, usually resulting in a Deck Out.

Origin
This name "Mill Deck" comes from Millstone, a card in the first widely-popular TCG, Magic the Gathering. Millstone allows the user to put three cards from the top of one player's deck (or, "library" in Magic), into their graveyard; there are dozens of other cards like this Magic, but because Millstone was the first, the act of putting cards from the deck into the discard pile directly became known as "Milling." Decks that centered around the alternate win-condition of depleting one's opponents' decks of cards became known as "Mill Decks," a term that has since spread to most other card games with this win condition.

Typical Cards Used
It is best to either mill through your opponent's deck quickly, have more cards in your deck than your opponent does, or fill your deck up with cards like Pot of Avarice or The Transmigration Prophecy.
 * "Book of Eclipse"
 * "Assault on GHQ"
 * "The Bistro Butcher"
 * "Chainsaw Insect"
 * "Card Destruction" (Which can be vicious when combined with Serial Spell)
 * "Cyber Jar" Traditional Only
 * "DNA Checkup"
 * "The Gift of Greed"
 * "Hand Destruction"
 * "Hiro's Shadow Scout"
 * Most "Iron Chain" monsters or cards
 * "Morphing Jar"
 * "Morphing Jar #2"
 * "Needle Worm"
 * "Greed"
 * "Necroface"
 * "Goblin Zombie"
 * "Robbin' Zombie"

"Gravekeeper's Servant", "Don Zaloog", "Sasuke Samurai #3", "Cup of Ace", etc, are also helpful. "Destiny Hero - Defender" makes your opponent draw a card during their Standby Phase while offering the highest DEF for a Level 4 monster. "Chainsaw Insect" is an offensive counterpart to "Destiny Hero - Defender", with 2400 ATK at Level 4. "Night Assailant" can also help you bring back "Needle Worm", "Morphing Jar", and "Morphing Jar #2". "The Shallow Grave" is also helpful for re-using Flip Effect Monsters, also "Dark Bribe" can be very useful, it negates 1 your opponent's spell or trap card and let's them draw an extra card. "Book of Eclipse" is also very good in stopping a swarm of monsters from attacking you while at the same time putting all monsters including your own into face down defense position, then at the end phase your opponent must flip all their face down monsters face up while drawing a card for each one flipped face up in this manner. this also a very good way to counter-act "Red Dragon Archfiend" when destroying all defense position monsters for the fact it puts all you opponent's monsters into defense position as well to feel the effect. Also, even though "Kuraz the Light Monarch" may be out of place among level four or less flip effect monsters, he will alow you to destroy two cards on the feld and make your opponent draw two cards.

The newly released "Iron Chain" cards in Crossroads of Chaos also aid this purpose. Another useful card from the OCG released in the TCG Crossroads of Chaos is the Virus Cannon.

When "Necroface" is removed from play, it removes five cards off both player's deck. With the release of Crimson Crisis Special Edition, "Necroface" is a promo card, and more available than in the past.

Another strategy is to have 3 Soul-Absorbing Bone Towers in play (most likely summoned with Inferno Reckless Summon), then suicide a Pyramid Turtle to bring out another Pyramid Turtle (This combo will mill out 6 cards at a time), then repeat the step until you're at your last one and then activate The Transmigration Prophecy or Pot of Avarice to return the other ones in the Graveyard back to your deck, and if this step is repeated it is possible to end the duel in one turn (One Turn Mill). It is optional to have a Spirit Barrier or a 4 countered Clock Tower Prison in place to protect your life points, and using Cold Wave will ensure a successful attack.

This type of Deck can be deadly against the popular Lightsworns, as they mill themselves as well. As a result, Mill decks can achieve victory extremely quickly against Lightsworns. However Lightsworns thrive on sending their cards to the graveyard, and if you're not careful their "Judgment Dragon" might end the duel faster the you can mill all of their cards. In order to avoid this problem you might want to side cards like "Dimensional Fissure" or "Macro Cosmos."

Greed Mill
This deck is consist of normal Mill deck with Greed in it. This deck is more focused on damaging the enemy with the effect of Greed. You should avoid cards that makes you draw such as Hand Destruction and Morphing Jar or cards that discards cards from the enemy's deck to the graveyard such as Robbin' Zombie, Assault on GHQ and Gravekeeper's Servant as they hinder or are not very practical cards to abuse the effect of Greed (The first problem could be solved by Solemn Wishes though). It is still highly suggested not to fill your decks cards that make you draw even if you have Solemn Wishes as the effect of Greed takes effect for every card drawn and Solemn Wishes only takes effect in a whole.