Historical Rules · 23 January 2015
Rule 208.4
Official source text from the 23 January 2015 Rules release
Effects that set a creature’s power and/or toughness to specific values may refer to that creature’s “base power,” “base toughness,” or “base power and toughness.” Other continuous effects may further modify the creature’s power and toughness. See rule 613, “Interaction of Continuous Effects.”