Error Card

An error card carries a true factory mistake: a missing energy symbol on an attack, wrong or swapped text, an incorrect rarity symbol, or artwork elements that should not be there. Famous examples from the vintage era include Base Set cards with missing or incorrect details that were fixed in later print runs.

Errors that were corrected mid-print are the interesting ones, because the mistake defines a distinct, countable version — the uncorrected copies become collectibles in their own right. This differs from a misprint, which is usually a one-off production accident like a miscut or ink smear. For expensive errors, documentation matters: well-known, catalogued errors are far easier to sell than obscure claimed ones.