Planeswalker cards are a unique type of card in the trading card game Magic: The Gathering. They represent powerful allies that players can summon to aid them in battle. Each planeswalker has its own set of abilities, which can be activated during a player's turn, allowing for strategic gameplay. When a planeswalker enters the battlefield, it comes with a specific number of loyalty points. Players can use these points to activate the planeswalker's abilities, which can include dealing damage, drawing cards, or creating creatures. If a planeswalker's loyalty points drop to zero, it is sent to the graveyard.