.YDC File Extension
What is a YDC file?
File used by Yu-Gi-Oh! Power of Chaos, a fantasy trading card game adapted for computers; contains a card deck that has been created by a game user; allows users to save and load different assortments of card decks for game play.
YDC files can be found under the profiles\[avatar name] directory of a Yu-Gi-Oh! installation. They may be exported and imported with other Yu-Gi-Oh! installations.