4th Ed Overrun attacks

[Matt W]

Assault "movement" is actually a fire action.  As such it is exempt from the requirement to move only one unit at a time.  As a result, extended assault can involve multiple units "moving" into the assault hex in a single action.

Overrun is specifically designated as a movement action and therefore, as in all movement actions, each unit must move, and therefore assault, individually.  If multiple AFVs are given a movement order with the intention to overrun that darn mortar platoon holding the road and the first overrunning tank causes the mortar to vaporize, the remaining activated AFVs can move to other locations.  If the mortar maintains its cohesion subsequent activated AFVs can use their movement to overrun the mortar until the desired result is reached, other objectives seem more valuable, or all activated AFVs have completed their actions.

The goal of overrun is not the obliteration of the defending unit but actually a way to deliver some punishment without sacrificing all mobility.  Note that after the overrun assault the attacking player actually vacates the assault hex.  The concept was added to point out that AFVs could and did run through defending lines without stopping.  The attacker risks a negative combat result in order to pass through a defended hex.  The fact that the defender may be injured by the passing AFVs is secondary.

If you are thinking why such an option would be considered by the attacker I would suggest that its use in many "enter & exit" scenarios will provide the attacker with a significant reason.  AFV steps generally count double in such victory conditions so the opportunity to run through the last defending line rather than having to stop and assault, clear the hex, or give up a couple turns in infiltration leaving behind yet another unit, provides an clear advantage.

My use of a mortar in the above example is due to the tactic of using a thin line of light units including mortars to screen objectives such as an exit hex, requiring assault to clear the hex before AFVs could penetrate.  Critics of the rules correctly indicated that tanks would not be deterred by a few mortarmen holding a 200 meter section of the line.