Historical Rules · 4 October 2019
Rule 107.3i
Official source text from the 4 October 2019 Rules release
If an object gains an ability, the value of X within that ability is the value defined by that ability, or 0 if that ability doesn’t define a value of X. This is an exception to rule 107.3h. This may occur with ability-adding effects, text-changing effects, or copy effects.