I originally posted this over on boardgamegeek.com, felt it was worthy of a repeat here...
Twin Shadows expansion
HABITATHabitat is a keyword found on certain Deploymentcards. During a campaign, when the Imperial playeris selecting open groups for a mission, he can choosea Deployment card with the Habitat keyword only ifthere is at least one tile in that mission’s map whose typematches the listed Habitat.Note: During a skirmish, Habitat has no effect.