When you are the attacker, minefields might only be useful occasionally. But for a defender they can delay and stall nicely. The same applies to blowing up bridges.
Beware, my first attempts to lay minefields ended in me trapping my own Engineer as I couldn't pass through my own fields.
I perhaps mined too much on Bataan and in Warplan Orange 3, the 2nd and 3rd US scenarios. Each mine field or to blow up a bridge costs 10 resources.
I mined the western part of the map, but will try again and see if I can't use that for even better effect on the eastern side of the Bataan map.
