Gadget

"Gadget" (ガジェット Gajetto) is an archetype of mostly Level 4 Machine monsters. There are two main groups of "Gadget" cards.

Colored Gadgets: "Green Gadget", "Red Gadget", "Yellow Gadget", "Gold Gadget", and "Silver Gadget". These cards are used by Yugi Muto. They are also closely related to the "Ancient Gear" archetype in terms of support, as seen in cards such as "Ancient Gear Reactor Dragon".
"Morphtronic" support: "Gadget Hauler", "Gadget Driver", and "Gadget Arms". These cards are used by Leo.

One other Gadget card, the "Gadget Soldier", is used by Seto Kaiba.

Members

Color

Gadget	Trap Monster
Platinum
Gold	Metalhold the Moving Blockade
Silver	Metalhold the Moving Blockade
Green	Stronghold the Moving Fortress
Red
Yellow

Morphtronic

Card	Origin
Gadget Arms	Toy gun
Gadget Driver	Screwdriver
Gadget Hauler	Truck
Gadget Gamer	Gaming computer / laptop

Playing style

The most common way to play the "Gadget" archetype is to use it with "Machina" cards. A Machina Gadget Deck focuses on bringing out "Machina Fortress" on to the field, generating a constant stream of Gadget monsters through "Green", "Red" and "Yellow Gadget", maintaining advantage over the opponent. With the advent of "Gold" and "Silver Gadget", the player can get another "Gadget" monster on to the field more quickly.

Main Deck monsters

The most important monsters of the Deck is obviously the colored "Gadgets" since they can fill up your hand with another Level 4 "Gadget" and swarm the field.

Some monsters that helps swarming further include:

"Kagetokage" and "Tin Goldfish". The player can then Xyz Summon "Gear Gigant X" to add another "Gadget", "Machina Gearframe", or "Tin Goldfish" from the Deck to the hand; alternatively, if using "Kagetokage", they can Xyz summon "King of the Feral Imps" to retrieve another "Kagetokage", ensuring they can Xyz summon another rank 4 monster next turn when combined with their constant supply of gadgets.
"Machina Megaform" can Tribute itself for "Machina Fortress".
"Speedroid Menko" can help you to buy some time for setting up if there are no monsters on the field and you do not have any "Gadget" monsters in your hand.
"Jumbo Drill" can help the player go for a "Cyber Dragon Nova" or "Digvorzhak, King of Heavy Industry".

Extra Deck monsters

The Xyz Monsters you should go into are:

"Gear Gigant X": This card can add 1 "Gadget" from your Deck to your hand.
"Castel, the Skyblaster Musketeer": You can bounce any card your opponent controls, thus disrupting their strategy
"Cyber Dragon Nova" -> "Cyber Dragon Infinity": "Infinity" can be a good beater, also it can negate and destroy a card effect once per turn.

As for Synchro Monsters, you can use "Turbo Synchron" and go for a "Stardust Spark Dragon" or "Ally of Justice Catastor".

"Missus Radiant" can help boost the ATK of "Machina" monsters as well as add 1 EARTH monster from the Graveyard to your hand. "Proxy Dragon" helps protect a card you control from destruction by destroying a card it points to instead. "Tri-Gate Wizard" offers double battle damage and protection from effects, as well as removal of a potentially dangerous card.

Notes

The "traffic light" Gadgets all have mist surrounding them matching the color of the card that searches them, and eye color and background gears matching the color of the card they search.

Recommended cards

Extra Deck

Synchro Monsters

Xyz Monsters

Link Monsters

Weakness

While this Deck can be strong, cards like "System Down" and "Acid Rain" will destroy all three "Gadgets" and all "A-to-Z" monsters. "Malfunction", "Mystical Space Typhoon", "Royal Decree", and "Trap Reactor・Y FI" (which also inflicts burn damage) would prevent "Stronghold the Moving Fortress" from appearing in the field. Sliding cards like "Imperial Order" and "Imperial Custom" (try to get this card out instead) can counter these cards.