Heroic Task:

" Action: Remove 3 resource tokens from this card and sacrifice it to take the card attached to it into your hand. If that card is an Artefact support card, you may attach it to a Hero or legend instead."

Iron Discipline:

"Action: Target one unit. Until the end of the turn, cancel any other action that targets this unit unless the action's controller pays an additional 4 resources (per action)."

Can Iron Discipline cancel the effect of heroic task? For example if i want to attach an artefact on a hero via heroic task and my opponent plays iron discipline on this hero in reaction. The text of heroic task says nothing about "targeting" but it should. Also attaching stuff always needs a target and this confuses me a little. Thanks in advance.

No target, no discipline. This is probably intended by FFG.

I agree with Virgo on this. I would also disagree with the statement that Heroic Task should say it targets.