Historical Rules · 23 July 2021
Rule 711.2a
Official source text from the 23 July 2021 Rules release
“{LEVEL N1-N2} [Abilities] [P/T]” means “As long as this creature has at least N1 level counters on it, but no more than N2 level counters on it, it has base power and toughness [P/T] and has [abilities].”