Cactus Game Design Message Boards

do you have to discard ram's horn if your rescue attempt is sucessful?
Ram's Horn:
Type: Artifact • Brigade: None • Ability: None • Class: None • Special Ability: Enhancements used by good Priests and warrior class Heroes cannot be interrupted. If your rescue attempt is successful, discard this card and one single-color Site from each opponent’s territory. • Identifiers: None • Verse: Exodus 6:5 • Availability: Priests booster packs (Rare)

You...kind of posted the ability on the card:

Ram's Horn:
Type: Artifact • Brigade: None • Ability: None • Class: None • Special Ability: Enhancements used by good Priests and warrior class Heroes cannot be interrupted. If your rescue attempt is successful, discard this card and one single-color Site from each opponent's territory. • Identifiers: None • Verse: Exodus 6:5 • Availability: Priests booster packs (Rare)

unless I'm misunderstanding the question.

what if there isn't a site to discard?

Then you don't get to discard a Site.  You complete as much as you're able.  If Ram's Horn is the only thing available to discard it's all you discard.