Historical Rules · 4 October 2019
Rule 208.1
Official source text from the 4 October 2019 Rules release
A creature card has two numbers separated by a slash printed in its lower right corner. The first number is its power (the amount of damage it deals in combat); the second is its toughness (the amount of damage needed to destroy it). For example, 2/3 means the object has power 2 and toughness 3. Power and toughness can be modified or set to particular values by effects.