Discard effects are mostly found in Darkness attribute cards and served as disruption or reducing the options the opponent's have in their hand as a preventive measure.
Discard effects also appear on Fire attribute cards, but it's more of a drawback or cost than a benefit. However, some cards can turn this "drawback" into "utility" that can benefit a player if used right.
- To "discard a card" is to move a card from your hand to your graveyard.
- If something says "discard hand" without any number of specific cards, that player discards all cards in their hand. If they don't have any cards in their hand at that time, it's still considered to be "discarded".