Rock (岩石Ganseki) monsters are an often-overlooked Type, though there were many released in The Lost Millennium. Usually, Rock monsters belong to the EARTHAttribute 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.
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".
"Megarock Dragon" and "Gaia Plate the Earth Giant" rely on removing from play monsters in the graveyard to special summon themselves, which can be extremely useful when mixed with "Release from Stone", which special summons a rock monster from the banished zone. Cards that take away the ability to banish cards from the graveyard pose a serious threat to some rock decks.
Rock Anti-Meta (commonly referred to as "Rock Stun") Decks use Rock-Type and other monsters that have meta-breaking effects to counter the current Metagame. The Deck can be played in a variety of ways. Some builds splash Rock monsters into a standard Anti-Meta build with cards such as "Thunder King Rai-Oh", "King Tiger Wanghu" and "Doomcaliber Knight". Other builds focus on a more aggressive play style, often using only Rock monsters and playing "Solidarity" to gain 2700 ATK "Koa'ki Meiru" monsters and a 2000 ATK "Fossil Dyna Pachycephalo". Still other builds use a pseudo-Macro Cosmos Deck to counter common effects that resolve in the Graveyard, while using cards such as "Release from Stone" and other cards like "Core Blast" to set up combos and gain field advantage, while using the "Koa'ki Meiru" monsters to hinder the opponent's strategies.
This deck uses the bounce effect of Golem Sentry to continually return the opponent's monsters back to their hand, leaving them open to attacks by stronger rock monsters. Gigantes works well because of its high 1900 ATK and its ability to be Special Summoned also working as a possible Spell and Trap removal. Also the Effect of Mirage Dragon will help allow Direct Attacks without worrying about Traps. Giant Rat works to keep Monsters on your side of the Field. Its ability to Special Summon Golem Sentry, Criosphinx, Moai Interceptor Cannons and Neo-Spacian Grand Mole gives you great flexibility.
This Deck utilizes the card powerful Rock beatsticks like: Koa'ki Meiru Guardian, Koa'ki Meiru Wall, Gogogo Giant and Koa'ki Meiru Sandman. One of the major differences between this Rock Deck and other Rock Decks, is that it special summons. While most Rock decks rely on flip effects to take down the opponent, this deck relies on swarming the field with huge beatsticks and/or several rock floaters that provide both field advantage and a host of power plays. It's key card is Block Golem. This card allows you to summon any two level four or lower rock type monsters from your graveyard by sending itself to the graveyard. From here you have access to rank 3 and 4 xyzs like Acid Golem of Destruction, Gem-Knight Pearl and the like. Its has two ace monsters: Gaia Plate the Earth Giant and Grandsoil the Elemental Lord. other cards that may be useful for this deck due to their easy summoning requirements and/or deck thinning abilities are Naturia Cliff, Naturia Rock, Chronomaly Crystal Bones,and Chronomaly Crystal Skull. It is recommended that the deck is comprised of earth type monsters, as Block Golem cannot activate its effect if there are any other attributes in the graveyard. You can use several spell and trap cards to dump rocks from your deck to the graveyard to fulfill the summoning requirements for the ace cards in the deck.