Mines 3

Note that the minefield owner always rolls for the unit moving into the
minefield so that it's nature is not given away. (Oh, you rolled a 51 and I
wasn't attacked, so it must have a 50% chance of encounter.) Sorry, but no.

Types of minefield:
    Protective.  Easily emplaced and removed, used for close-in
protection against an enemy's final assault. Integrated into a company or
platoon's defensive positions. Usually fairly shallow and of greatly variable
density. A good average might be 50% chance of encounter. May consist only of
AP mines, in which case vehicles can ignore. Phony: As per type of minefield
simulated, except when the defender rolls the dice to tell whether or not the
unit was attacked, it never is. Tactical: Covered in it's own post! Nuisance:
Subset of tactical. Small and irregular, generally small. 50% chance of
encounter. For game purposes, tied to a terrain feature, eg. "The crossroads
between Hill 204 and Hill 402"