Spell cards are special cards used in various trading card games, such as Yu-Gi-Oh! and Magic: The Gathering. These cards represent magical abilities or effects that players can use during their turn to influence the game. Each spell card has specific rules and conditions for use, often providing advantages like dealing damage, drawing extra cards, or altering the game state. Players typically include spell cards in their decks to enhance their strategies and counter opponents' moves. The effectiveness of a spell card can depend on its timing and the current game situation, making them a crucial element in gameplay and deck-building.