A rules engine for your prototype, not somebody else's game
No commercial game's deckbuilding rules, rarity system, ban list, or intellectual property is embedded. The checker only applies the limits and category names you enter.
Rows and copies are not the same
A single row may represent several physical copies. Totals, category ranges, and per-ID limits therefore use the quantity field. Duplicate IDs are combined for copy-limit checking while the report still exposes structural problems.
Related checks
Use the CSV Schema Validator for richer field rules and the Version Diff Generator to document a revised set.