good strategy game for the family

A strategy game where we choose our people and where we go to conquer different territories. We play mostly to 4, 2 adults and 2 children aged 6 and 12 years. Even at 6 years old, my son loves this game and is doing, you just sometimes help him in his choice. You can play 2, but we are many, the better. A 4, the game lasts almost 3 hours, taking her time. To enjoy this game, you have to like heroic fantasy creatures, dwarves, elves, undead, gnomes ... This game makes you think most young people, makes them understand the concept of territories and sometimes allows them to earn their parents!