711.2 A level symbol is a keyword ability that represents a static ability. The level symbol includes either a range of numbers, indicated here as “N1-N2,” or a single number followed by a plus sign, indicated here as “N3+.” Any abilities printed within the same text box striation as a level symbol are part of its static ability. The same is true of the power/toughness box printed within that striation, indicated here as “[P/T].”
711.2a
“{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].”
711.2b
“{LEVEL N3+} [Abilities] [P/T]” means “As long as this creature has N3 or more level counters on it, it has base power and toughness [P/T] and has [abilities].”