Rock

Rock monsters are an often-overlooked Type, though there were many released in The Lost Millennium series. Usually, Rock monsters belong to the EARTH Attribute and possess high DEF and defense-related Card effects. A significant number of Rock monsters have effects related to Flip Summoning or have the ability to flip themselves face-down again.

Archetypes include Fossil, Monk, Piece Golem, the Hex-Sealed Fusion family, the Magnet Warrior cards and Sphinx cards.

Some of the more notable cards include: "Castle Gate", "Enraged Muka Muka", "Exxod, Master of The Guard", "Gaia Plate the Earth Giant", "Gigantes", "Gladiator Beast Hoplomus", "Granmarg the Rock Monarch", "Guardian Sphinx", "Legendary Jujitsu Master", "Megarock Dragon", "Mine Golem", "Moai Interceptor Cannons", "Muka Muka", "Multiple Piece Golem", "Neo-Spacian Grand Mole", "Rockstone Warrior", "Sand Moth", "Stone Statue of the Aztecs" and "Valkyrion the Magna Warrior".

With the introduction of the "Koa'ki Meiru" archetype, Rock-types gained some high-ATK monsters focused on heavy control. "Koa'ki Meiru Guardian" allows negation of monster effects, "Koa'ki Meiru Sandman" can negate Trap Cards and "Koa'ki Meiru Wall" can negate Spell Cards. Each with 1900 ATK points, these three can be used to switch from the classic defensive builds to more aggressive builds. They can be searched with "Koa'ki Meiru Boulder", also a Rock-type. With monster destruction available via "Mormolith", and some Anti-Meta capabilities with "Fossil Dyna Pachycephalo", Rock Decks can take the offensive or get a solid defense, easily switching between these strategies.

Four Field Spell Cards exist that work particularly well with Rock monsters. "Wasteland" increases the ATK and DEF of Rock monsters by 200, "Canyon" inflicts double Battle Damage to anyone attacking a Defense Position Rock monster with a weaker monster, "Gaia Power" increases the ATK of EARTH monsters by 500 points, though it weakens their DEF, which is often an important part of Rock Monsters' strategy, and "Acidic Downpour" which is the reverse of "Gaia Power", decreasing their ATK by 500 but making them gain 400 DEF. The ATK decrease can be seen as a bonus if the Deck is only defensive, since it will probably be lowering your opponent's monsters ATK, as EARTH is a very common Attribute. "Chorus of Sanctuary" can be used as an alternative to "Acidic Downpour" if the Deck is more offensive. Rock-Type monsters are also weak against the card, "Breath of Light".

They also have their own Structure Deck, Structure Deck 7: Invincible Fortress.

With the release of "Return of the Duelist" in the OCG, there are more support for Rock Monsters. "Rock Launch Area", a new Field Spell Cards that can be used to fill your Graveyard with Rock Monsters and prevent Destruction. "Sandcloud Knight", as "Armageddon Knight" for EARTH Monster, also useful for dumping, so later can be revived through "Block Golem" effect.

The only main character in the anime to use a Rock Deck is Jim Crocodile Cook, although other characters do use Rock-Type monsters. Yugi Muto uses the Magnet Warriors, Jaden Yuki uses "Neo-Spacian Grand Mole", Yusei Fudo uses "Rockstone Warrior", Jack Atlas uses the Piece Golems and Power Giant and Yuma Tsukumo uses "Gogogo Golem".