A spell system is a framework used in role-playing games and fantasy literature to define how magic works. It typically includes rules for casting spells, the types of spells available, and the resources required, such as mana or spell slots. Players can choose spells based on their character's abilities and the game's mechanics, allowing for strategic decision-making. Different spell systems can vary widely, with some focusing on elemental magic, while others may include healing or summoning spells. Popular examples of spell systems can be found in games like Dungeons & Dragons and Final Fantasy, each offering unique approaches to magic and its limitations.