well max copies in ygo is 3, and in Magic is 4; I managed to beat this game with with a deck containing ONLY 2 COPIES OF STILETTO, this card is insainely broken and loops into itself.
The consumable food cards helped a lot in creating this clicking frenzy deck.
Crazy how this game is getting plays two years after I made it! You're definitely right that stiletto was broken, but making a game in a weekend will do that to ya! In the future I'd make food not count towards deck size and perhaps instead of limiting card counts just make them harder to get.
