Planeswalkers are among the most powerful cards in Magic. They're also some of the most difficult cards to play with or against. Every turn, the player who controls a planeswalker has anywhere from one to four options as to how to utilize it, while the opposing player now has three options for each attacking creature rather than two. When you start adding more planeswalkers to the battlefield, the raw complexity of the game multiplies out of control.
War of the Spark seems to be heading towards a world where games of that level of complexity are commonplace. Aggro, control, and midrange decks alike continue to incorporate more powerful planeswalkers from the latest set, and we've even seen a return of the SuperFriends archetype, layering various static effects from new planeswalkers to create a prison of sorts, stymying the opponent's ability to function while your material advantage snowballs turn after turn.
In this new planeswalker-dominated Standard world, it's increasingly important to know how to evaluate the complex battlefields planeswalkers generate and efficiently dispose of them. To do this, there are some common heuristics that successful players use which you should take to heart and incorporate into your deckbuilding choices and play patterns over the next three months.
There are four distinct ways to answer a planeswalker: counterspells, planeswalker removal spells, direct damage spells, and the combat step. The first three all involve trading a specific card or cards for the planeswalker, but it's the ability to interact with them during combat that makes planeswalkers so unique, so let's start there.