|Japanese (base text)||
A Maximum Monster (Japanese: マキシマムモンスター Makishimamu Monsutā) is a type of Monster Card in Yu-Gi-Oh! Rush Duel. Like Effect Monsters, they are colored orange. They were first introduced in the Yu-Gi-Oh! SEVENS anime, and revealed in full for Yu-Gi-Oh! Rush Duel.
Maximum Monsters are stored in the Main Deck. They can either be Normal or Special Summoned normally, or they can be Summoned via a special procedure called Maximum Summoning. If the player has three specific Maximum Monsters in their hand, they can Maximum Summon them together in Maximum Mode; as this is a form of Special Summoning, no Tributes are required even if one of the Maximum Monsters is Level 5 or higher. However, if the player already controls one or more monsters, then they must send them to the Graveyard as part of the Maximum Summon.
Under Maximum Mode, the three Maximum Monsters are treated as one single monster, with the center Maximum Monster's Level, Type, and Attribute applying, and the MAXIMUM ATK value that is printed on the center Maximum Monster intead of the normal ATK value applying. Maximum Monsters in Maximum Mode do not possess DEF, and cannot exist in Defense Position. Maximum Mode is also the requirement to apply or activate the effects of Maximum Monsters. The Maximum Monsters in Maximum Mode can activate/apply all three of the effects of their component cards, but they can only attack once per turn, and are only treated as one Tribute for a Tribute Summon.
The three specific Maximum Monsters all share the same name, with a "main" center card that possesses the MAXIMUM ATK value of the trio printed above its ATK/DEF, and two other monsters that have either [L] or [R] printed after their name, denoting the Left and the Right cards. Thus far all center Maximum Monsters have been Level 10, while the [L] and [R] monsters have been low-Level.
In the anime, Maximum Monsters were created by Nail Saionji, who noted a gap in the code of Rush Dueling that had been left there by the format's creator, Yuga Ohdo. Nail installed the rules for Maximum Summoning using Real-Time Rush Duel Programming during his Rush Duels with five of the Tops of Hexagon, and used Maximum Monsters against Yuga. All of them have been created by rewriting Duel ID cards, due to the cards' own ability to be overwritten with new card data.
- yu-gi-oh.jp What Is A Maximum Monster (japanese)