Canceling King Arthurs boosted attack on cards with no effects

Question

In Unmatched: Battle of Legends Vol 1 King Arthur has a special ability:

When King Arthur attacks, you may BOOST that attack. Play the BOOST card, face down, along with your attack card.

If your opponent cancels the effects on your attack card, the BOOST is discarded without effect.

One of King Arthurs cards is Excalibur. There is no effect on the card just a title. If my opponent plays a card that happens to cancel any card effects would a Boosted Excalibur lose the boosted bonus?

Answer 1

From Jenn S. at Restoration Games

Essentially, Arthur's special ability is an effect that can get canceled, so the Boost would be discarded.

There is some further discussion on it in this BoardGameGeek thread: Feint vs boosted Excalibur.

TL;DR even with Excalibur, the boost would be discarded if an opponent's card discards effects.