Synchro Monsters (Japanese: シンクロモンスター Shinkuromonsutā, abbreviated Ｓシンクロモンスター in card text since Duelist Alliance) are a type of Monster Card, first released in Starter Deck 2008. The color of their card frame is white. These cards are placed in the Extra Deck.
To be properly Special Summoned, Synchro Monsters must be Synchro Summoned. To be Synchro Summoned, the player must send, from their side of the field to the Graveyard, a face-up Tuner monster and one or more face-up non-Tuner monsters, whose total Levels exactly equal the Level of a Synchro Monster. The monsters used in the Synchro Summon are called Synchro Materials.
Like other Extra Deck monsters, Synchro Monsters cannot exist in the hand or Main Deck (even with card effects). If a Synchro Monster would be moved to the hand or Main Deck, it is returned to the Extra Deck instead. If a card like "Transmigration Break" or "Degenerate Circuit" is applying, this will override the Synchro Monster's ability to return to the Extra Deck.
Like other Extra Deck monsters, if a Synchro Monster is not Synchro Summoned first, it cannot be Special Summoned from the Graveyard or while banished (unless it specifies another way to properly Special Summon it).
Similar to how Synchro Monsters replaced Ritual and Fusion Monsters when Yu-Gi-Oh! 5D's started, Xyz Monsters replaced Synchro Monsters when Yu-Gi-Oh! ZEXAL started.
However, whilst Synchro Monsters did not appear in the ZEXAL anime or manga, additional support for Synchro Monsters still appeared on occasion in the TCG although the primary focus of all ZEXAL-era products was Xyz Monsters. The TCG version of the booster packs Generation Force, Order of Chaos, Photon Shockwave and Cosmo Blazer all included 1-3 new Synchro Monsters despite primarily containing Xyz Monsters. Synchro Monsters also have been on occasion released in the 2012 Collectors Tins as promo cards and new Synchros were still released in several Hidden Arsenal sets, Hidden Arsenal 5: Steelswarm Invasion and Hidden Arsenal 6: Omega Xyz. The latest addition in Gold Series, Gold Series: Haunted Mine contained reprinted Synchro Monsters as well. The Premium Collection Tin also included 3 new Synchro Monsters, and several Synchro Monsters were reprinted in the 2013 Collectors Tins. Judgment of the Light, however, marked the first time since Xyz Monsters came into the game that Synchro Monsters gained much support and new monsters, featuring 8 new Synchros, about the same number released per set during the Yu-Gi-Oh! 5D's era of the TCG. One of the newest Structure Decks, Saga of Blue-Eyes White Dragon Structure Deck features a "Blue-Eyes White Dragon" Synchro Counterpart ("Azure-Eyes Silver Dragon"). Shadow Specters and Legacy of the Valiant released 4 and 3 Synchro Monsters respectively, including brand new, splashable and generic ones, such as "Giganticastle" and "Leo, the Keeper of the Sacred Tree", TCG-exclusives, like "Powered Inzektron", and Synchro monsters that only existed in the OCG, such as "Celestial Wolf Lord, Blue Sirius".
However, beginning with Duelist Alliance, the set after Primal Origin (which is the last Yu-Gi-Oh! ZEXAL-based set), it has been advertised by Konami that Synchro Monsters, Xyz Monsters, Ritual Monsters and Fusion Monsters will begin getting an equal amount of support. More Synchro Monsters that were formally OCG-exclusive were also recently finally released in the TCG Premium Gold and after on Premium Gold: Return of the Bling sets, along with many reprints of old Gold Series Synchro Monsters.
Despite the advertisement that the support would become the same, it was in the 9th series that the "Yang Zing" Archetype was released; this archetype is the only one that relies entirely on Synchro Summoning since the release of the "Synchron".
In the anime
Synchro Monsters have the power to manipulate Ener-D, allowing humans to accelerate their evolution. It was a vital part of the plot of Yu-Gi-Oh! 5D's and the series antagonists' intentions. However, it was never explained exactly how Synchro Monsters obtained this ability.
A possible theory is linked to the statement that Synchro Monsters are the "symbols of human evolution". This could be the case when one considers how intricately linked humanity is to Duel Monsters and Ener-D. It is stated by Jakob that man's excessive use of Synchros caused Ener-D to spin faster, producing more energy and thus accelerating human evolution. It could be that this energy is fueling human evolution because of Synchros, the "symbols of human evolution". Humanity expresses its subconscious desire for evolution by obsessing over and excessively using Synchro Monsters.
While no Synchro Monsters appeared in Yu-Gi-Oh! ZEXAL, Yu-Gi-Oh! ARC-V has shown one Synchro monster in the first episode, "XX-Saber Gottoms," which appeared later in the series used by "X-Saber" Duelist Kit Blade. Declan Akaba has also used a Synchro Monster, and Yugo uses a Synchro Deck, while Gong Strong has added Synchro Monsters to his Deck. They are said to be monsters that only the elite use and they are the only type of Extra Deck monster used in the Synchro Dimension.
Subgroups of Synchro Monsters
In the anime, manga, and some video games, there are cards with a monster card type other than "Synchro" listed on the Type/ability line.
Accel Synchro Monster
In the anime, Accel Synchro Monsters are Synchro Monsters that are Synchro Summoned by Accel Synchro Summon, which requires all of the Synchro Materials to be Synchro Monsters, so require Tuner Synchro Monsters. Due to the requirement of Synchro Monsters as materials, their Level is always high and they have powerful effects. Examples include "Shooting Star Dragon" and "T.G. Blade Blaster".
There are two subgroups of Accel Synchro Monsters: Limit Over Accel Synchro Monsters and Delta Accel Synchro Monsters.
Delta Accel Synchro Monsters are Synchro Summoned by Delta Accel Synchro Summon, which requires 3 or more Synchro Monsters as Synchro Materials (1 Tuner and 2 or more non-Tuners) and the player to be in a state of Top Clear Mind. The only examples are "T.G. Halberd Cannon" and "Cosmic Blazar Dragon" (although the latter was never seen).
Limit Over Accel Synchro Monsters are Synchro Summoned by Limit Over Accel Synchro Summon, which requires 3 or more Synchro Monsters as Synchro Materials (1 Tuner and 2 or more non-Tuners) and the player to be in a state of Over Top Clear Mind. The only example is "Shooting Quasar Dragon".
Dark Synchro Monster
In the anime and manga as well as the Tag Force video games, Dark Synchro Monsters are also a subgroup of Synchro Monsters. They are Synchro Summoned by Dark Synchro Summon, which uses 1 non-Tuner monster and 1 Dark Tuner monster, and Summons a monster whose Level is equal to the Dark Tuner's Level subtracted from the non-Tuner's Level, which is a negative number or zero. As such, all Dark Synchro Monsters have negative Levels or a Level of 0.
A Synchro Summon is the act of Summoning a Synchro Monster from the Extra Deck using a Tuner monster with additional non-Tuner monsters. During the Main Phase 1 or 2, the turn player can Synchro Summon a Synchro Monster from the Extra Deck by sending monsters they control to the Graveyard (at least 1 Tuner and 1 or more non-Tuner monsters), provided the total Level of those monsters matches exactly the Level of that Synchro Monster.
To perform a Synchro Summon, one Tuner monster and at least one non-Tuner monster must be used as Synchro Materials. Trap Monsters and Token Monsters can be used as Synchro Materials, with the Trap Monster "Shapesister" even being treated as Tuner monster. While the majority of the Synchro Monsters requires 1 Tuner monster and 1 or more non-Tuner monsters, many Synchro Monsters have different requirements.
Some Synchro Monsters have restrictions on the Synchro Materials that can be used. Restrictions can be placed on the following attributes of the Tuner monster:
Name (e.g. "Moon Dragon Quilla", "Life Stream Dragon", "Majestic Star Dragon")
Type (e.g. "Chaos King Archfiend", "Baxia, Brightness of the Yang Zing", "Trident Dragion", "Dragunity Knight - Vajrayana")
Attribute (e.g. "Beelze of the Diabolic Dragons", "Gungnir, Dragon of the Ice Barrier", "Vylon Sigma")
Both Type and Attribute (e.g. "Ancient Flamvell Deity")
Archetype (e.g. "Blackwing Armed Wing", "Daigusto Eguls", "Mecha Phantom Beast Jaculuslan")
Level (e.g. "Sea Dragon Lord Gishilnodon")
Monster card type (e.g. "T.G. Blade Blaster", "Azure-Eyes Silver Dragon", "Ignister Prominence, the Blasting Dracoslayer")
Some Synchro Monsters require 2 or more non-Tuner monsters to be Summoned, such as "Mist Wurm" or "Ally of Justice Decisive Armor"; in that case, at least 3 monsters are required. Other Synchro Monsters, such as "Dragocytos Corrupted Nethersoul Dragon", specify the number of non-Tuner monsters that are required.
Multiple Tuner Synchro Summoning
While most Synchro Monsters require exactly 1 Tuner to be Synchro Summoned, "Red Nova Dragon", "Hot Red Dragon Archfiend King Calamity", "Tyrant Red Dragon Archfiend" and "Vylon Omega" require 2.
"XX-Saber Gottoms" must be Synchro Summoned using a Tuner and EARTH monsters, but it does not specify that the EARTH monsters must be non-Tuners. Therefore, up to 5 Tuner monsters can be used for its Synchro Summon.
Tuner Synchro Monsters
Tuner Synchro Monsters are Synchro Monsters that are simultaneously Tuner monsters ([Type/Synchro/Tuner]); usually, they have effects that make Synchro Summoning easier, such as "T.G. Wonder Magician" and "Phonon Pulse Dragon"; the former allows its controller to Synchro Summon during the opponent's turn and the latter manipulates its own Level and restricts other kinds of Special Summon.
While some Synchro Monsters have restrictions on the Synchro Materials that can be used, many do not, or have lax restrictions, making them more splashable in decks than Fusion and Ritual Monsters, as many require just a single Tuner and another monster to Summon them, and almost any Deck can run a few Tuners.
Strategically speaking, Synchro Monsters allow for a large amount of rapid power to be Summoned with relative ease and speed. Most of them have very potent effects in addition to their ease in Summoning. They do not necessarily always have card advantage over Fusion Monsters, because a player might use up as many cards getting all of the Synchro Materials on the field to perform a Synchro Summon in one turn, but they have the advantage of increased flexibility and speed over Fusion Monsters due to the fact that many of them have very non-specific requirements for them to be Summoned, so a player with a Tuner monster and a non-Tuner monster on the field will always have one or more options for Summoning, especially if card effects that allow Levels to be changed are used.