Inis is a game deeply rooted in Celtic history and lore in which players win by being elected King of the Island (Inis). Players can try to achieve one of three different victory conditions:
- Leadership: Be the leader — i.e., have more clan figures than any other player — of territories containing at least six opponents' clans.
- Land: Have your clans present in at least six different territories.
- Religion: Have your clans present in territories that collectively contain at least six shrines.
Over the course of the game, players also earn deeds, typically chanted by bards or engraved by master crafters, that reduce by one the magic total of six for any condition. While one victory condition is enough to claim the title of King, a game of experienced players usually has a tight balance of power, emphasizing the leadership of the capital of the island.