Pioneer is a new nonrotating format where players build decks using cards from Return to Ravnica and Magic 2014 forward. Introduced in 2019, Pioneer received high-level tournament support right away, first on Magic Online, then at several major tabletop events starting in 2020.
The initial ban list of Bloodstained Mire, Flooded Strand, Polluted Delta, Windswept Heath, and Wooded Foothills made for a completely different kind of nonrotating format, allowing cards like Deathrite Shaman to roam freely without dominating. Nevertheless, Wizards announced plans to monitor tournament results closely and to update the list of banned cards frequently.