'''Series 1211''' is the collective name for the [[Core Booster]]s released from 2020 to 2023. As it coincides with ''[[Yu-Gi-Oh! SEVENS]]'' and ''[[Yu-Gi-Oh! GO RUSH!!]]'', which promote ''[[Yu-Gi-Oh! Rush Duel]]'', it is the first and only booster series to not introduce cards from any anime series into the ''[[OCG]]''/''[[TCG]]'', instead focusing on supporting already-existing themes from the first 6 ''[[Nihon Ad Systems|NAS]]'' anime series, from ''[[Yu-Gi-Oh! Duel Monsters]]'' to ''[[Yu-Gi-Oh! VRAINS]]'', with original cards (''Battle of Chaos'' introduced "[[Blue-Eyes Tyrant Dragon]]", which was [[Blue-Eyes Tyrant Dragon (anime)|referred as a monster]] in its own right in the English dub of the ''[[Yu-Gi-Oh! (anime)|Yu-Gi-Oh!]]'' anime, however, since it was not in the Japanese version, it is not counted).