Plains

Plains is legal in every format that exists, which tells you everything about its status: it is the baseline. In Commander, singleton rules make basics more important than in other formats, and Plains earns its slot in any deck with white in the color identity as a consistent, untappable, fetchable white source that never enters the battlefield tapped. In competitive formats like Legacy and Vintage, Plains sees almost no play outside mono-white or Death and Taxes shells, where basic land status protects it from Wasteland — a relevant edge in those specific metagames. In Standard, Pioneer, and Modern, Plains shows up as the backbone of white-based midrange and control decks, filling out land bases where the budget or the color demands basics.