|Appears in (anime)||
Union monsters (ユニオンモンスター Yunion Monsutā) are Effect Monsters with the ability "Union". Each Union monster has an effect that allows it to equip itself to a monster as an Equip Card or unequip itself to Special Summon itself to a Monster Zone.
They were introduced in Advent of Union in the OCG and Magician's Force in the TCG. A-to-Z is a series dedicated to Union monsters; the equip-themed "Vylon" archetype also contains several Union monsters.
Modern Union monsters all have the following effects:
- Once per turn, the player can either:
- If the monster equipped with this card would be destroyed by battle or card effect, destroy this card instead.
If a Union monster is equipped by a card effect other than its own, its equip effects will apply as normal.
A monster is only considered a Union monster if it is specifically listed as having that ability. Many monsters that can treat themselves as Equip Cards are not Union monsters, such as "Worm Millidith" and "Armory Arm".
Structure Deck: Seto Kaiba (SDKS) introduced several changes to common Union effects. These changes were applied to all Union monsters released or reprinted in Structure Deck: Seto Kaiba, and have been applied to all Union monsters released or reprinted in the OCG afterwards (but does not apply to Union monsters that have only been reprinted in the TCG). Union monsters that have not received this errata (i.e. have not been reprinted since Structure Deck: Seto Kaiba) retain their original effects.
Prior to the release of Structure Deck: Seto Kaiba:
- Union monsters can only be Special Summoned in Attack Position if they were Special Summoned with their own unequip effect.
- Many Union monsters can only redirect destruction if the monster they are equipped to would be destroyed by battle.
- Union monsters have a condition that only one Union monster can be equipped to a monster at a time.
- Union monsters' effects that apply while equipped do not apply if equipped by another card effect.
- Newer Union monsters tend to combine with Machine-Type monsters and are Machine-Type themselves.
- "Torque Tune Gear" is the only Union Tuner Monster in the game.