Expansion is the type assigned to an extension. You can check which expansion is assigned to an extension in MCH Dictionary or other sources.

In Duel Cups and other contents, there may be restrictions on the use of extensions based on the expansion. Restrictions can be found in the cup information.

Between the end of the previous year's World Championship and the start of the next year's qualifiers, we will announce which Extensions will be designated as Modern.

There are three types of expansions.

• Standard

Starting before the next WC series, the "Standard" category will be ntegrated into "Modern." and there will be only two categories: "Modern" and "Legacy."

• Modern

・All newly issued types of Extensions will be designated as Modern.

・An Extension designated as Modern will remain as Modern for a guaranteed period of two years from the year it was designated.

Ex 1: Extensions classified as Standard or Modern in 2024 will be classified as Modern until the end of 2025. Extensions classified as Standard in 2024 will be reassigned to either “Modern” or “Legacy” when the next new Expansion is released. If an Extension is classified as Modern during this reassignment, it will remain in the Modern category until the end of 2025, at which point a reassessment of the Expansion will be made for the following year. Please note that Extensions with high usage rates are expected to remain in the Modern category, while Extensions with lower usage rates that significantly increase team complexity may be moved to the Legacy category.

Ex 2: If an Extension designated as Modern in 2024-2025 is designated as Modern again in 2026, it will remain in the Modern category until the end of 2027.

・After two years have passed since the Modern designation, the Extension will either be re-designated as Modern or moved to the Legacy.

• Legacy

Extensions that are not Standard or Modern are assigned this expansion.

• Other points

Limited extensions are assigned the same expansions as the series.

All replica extensions are treated as Legacy.