Deck Regulations (
Applied only in Standard format.
- Main deck must contain cards from the same nation, with the additions below.
- Cards without a specified nation, such as "Spiritual King of Determination, Olbaria", may be used in any deck.
- Card Restrictions are applied.
- Both main deck and G deck must contain cards from the same clan, with the additions below.
- Cards with an ability causing them to be part of multiple clans may be used in a deck of any of their stated clans.
- «Cray Elemental» may be used with all clans and nations.
- «Royal Paladin» decks may include any number of "Blaster Dark".
- «Link Joker» decks may include any number of cards with "Я" in their card names.
- Cards that list a nation instead of a clan may be used with any clan that is within their nation. This includes <Zeroth Dragon> and "Progenitor Dragon" cards, and cards with the icon.
- If "Neon Gyze" is included in the main deck, the G deck may include any number of <Zeroth Dragon> cards.
- These restrictions only apply during deck construction. Therefore, if a card has its clan changed during the game, you may still use that card in the game regardless of its new clan.
- Card Restrictions are applied.
- All cards may be used regardless of clan or nation.
- "Epitome of Knowledge, Silvest" may be used regardless of the present date.
- Card Restrictions are not applied.
In the game's beginning
Originally, there were no fight formats, and cards were allowed to be used in any decks regardless of their clans. In fact, due to the small number of cards available at the time, some clans simply did not have enough cards to make a deck using only cards from their own clan. For example, the Great Nature clan was introduced in Booster Set 2: Onslaught of Dragon Souls, but no trigger units were released for it until Booster Set 7: Rampage of the Beast King, so clan mixing was until that point the only way to play the Great Nature clan in a deck.
At the same time, however, many of the more powerful cards had clan-based restrictions as part of their abilities, such as a [Power] penalty for controlling a unit of a different clan, the Lord keyword, or an ability that could only be used on cards of the same clan or if you controlled another unit of the same clan. These restrictions, along with the rule that trigger effects require a unit of the same clan on the field to activate, made it so that clan mixing was rarely done.
The Legion era
With the introduction of Legion in Booster Set 16: Legion of Dragons & Blades, the strategy of mixing clans, which was once rarely done, suddenly and unexpectedly became extremely powerful. To keep the power level of these decks under control, and to prevent further situations like this from occurring again, the Clan Fight regulation was implemented in February 2015. Clan-based restrictions and penalties within cards' abilities became unnecessary as a result, and soon afterward began to be no longer printed on cards.
Extreme Fight regulation introduced
The Extreme Fight regulation was created at the same time so that players who still wanted to play multi-clan decks could still do so. However, there have never been any official tournaments that have used the Extreme Fight regulation, and it is rarely played in practice.