The Irish Sea expansion extends the game's theater of operations to British isles region. "The Irish Sea" includes a new playing board with special land regions, and also several additional cards for each side of conflict. New components bring a much deeper strategic experience and multiple tactical possibilities to War of the Worlds: the New Wave. This expansion makes the gameplay even more tense, and we strongly recommend playing the base version several times, before adding this expansion's components. —description from the publisher