Example: In a 5-player game, everyone starts with 3 cards, then the first player draws a card. That means there are only 2 cards left in the deck. What happens if that player swaps a pair or pork or shrimp? Do they only get 2 cards? Or is the swap disallowed?
What if there are cards in the discard pile? Are you allowed to use them if the other pile is empty?
What if there are cards in the discard pile? Are you allowed to use them if the other pile is empty?