Planeswalkers are powerful beings in the Magic: The Gathering universe who can travel between different realms, known as planes. They possess unique abilities and spells, allowing them to influence the multiverse and interact with other creatures and characters. In the game, players can use planeswalker cards to summon these characters to the battlefield. Each planeswalker has a set of abilities that can be activated during the game, providing strategic advantages. They are often central to the game's lore, representing various factions and stories within the Magic: The Gathering narrative.