Lost Ruins of Arnak · Board game rules
When do you get double icons from Artifact cards?
Quick answer
Some cards, including artifacts, may simply be printed with two travel icons on them, which you can use together to pay a two-icon cost, or use one to cover a single-icon cost (wasting the other) [p.9 — Dig at a Site].
Details
The rulebook explains that if a travel cost requires two icons, you can cover it either with travel values from two separate cards or with a single card that happens to show two icons by itself [p.9 — Dig at a Site]. This isn't a rule unique to artifacts — any card in your hand could have this property — but artifacts are one type of card that can carry travel values just like basic and item cards [p.8 — Your Turn].
If a card with two icons is used to pay a cost that only requires one icon, the extra icon is simply wasted; it does not carry over to a future turn [p.9 — Dig at a Site].
Separately, note that artifact cards also have an unrelated feature: a resource cost printed in the corner for their effect. This cost is ignored when you first buy the artifact, but must be paid every time you use the artifact's effect later from your play area [p.13 — Play a Card]. This is a different concept from travel icons and should not be confused with the "double icons" travel rule.
Watch out: Don't confuse the artifact's effect cost (paid only when replaying the effect from hand) with travel icons (used to pay for actions like Dig at a Site). They are separate systems, and only the travel-icon rule relates to "double icons."