@Dukla:
You are saying that they are active just when the territory is controlled or contested by ‘‘home power’’ but how about the territory was in hands of ‘‘enemy power’’ and after is contested?
If the territory becomes controlled by an enemy power, the minefield becomes inactive. If the territory becomes contested again, the minefield becomes active again for the original controller. In effect, a mine field is only inactive when its corresponding territory is enemy-held.
@Dukla:
Because if I understand correctly the rules if there is a battle and everyone dies the territory still in ‘‘enemy hands’’ so thats why dont understand why I have to roll again for mines when is contested{before everyone dies}?
If both sides are eliminated in a battle for any territory with an original controller, the original controller regains control (regardless of who had control last). See the bottom of page 19 in the rulebook. The only exception is when the original controller’s capital is held by the enemy, in which case the liberator assumes control until the capital is liberated.