Trebuchet

The most effective siege unit, has a 5% chance per level to make hole in the wall. If failed there is 2% chance to destroy one level of a wall. If there is no wall, then target the castle. If that does not exist either, damage a random building. If that fails, then they have a 1% chance per level to damage a random building. Note: do not use trebuchets if you want to conquer city you are attacking theu can deal huge damage to buildings