An error card contains a mistake — a misspelling, a wrong stat, an incorrect photo, or some other manufacturing goof that creates an unintentional variation. And in the hobby, mistakes can actually be worth money.
Here's why: when the manufacturer catches the error and corrects it, the uncorrected error cards can end up being far rarer than the fixed version, which drives their value up. But there's a twist — if the correction happened late in the production cycle, the corrected version might actually be the rarer one. So with error cards, you've got to do your homework on print timing to know which version is the real chase.