More Foul Play

[slyther]

When using Zoroark's Foul Play to copy Landorus-EX's "Land's Judgement" attack:

:fighting::fighting::colorless: Land's Judgment 80+
You may discard all Fighting Energy attached to this Pokémon. If you do, this attack does 70 more damage.

Does Zoroark get to add the extra 70 damage even if it has no fighting energy to discard?

 

[PokePop]

No, you have to discard at least one Fighting energy.
It says "if you do".
So discarding zero energy does not qualify as doing anything.