Advanced Assault Shenanigans

Warhammer 39,999 wrote me today with:
During my assault phase I wish to charge a unit that's in partial cover. The closest model of that unit is within charge range and entirely not in cover. All other models in the unit are in cover, but are still within 6". When attempting to charge that unit, do I need to roll a difficult terrain test?
He also attached a handy diagram to show what he was talking about:My response:
Oh yeah, that's a fun little one. There's really two pertinent rules here:
BRB, page 34, Moving Assaulting Units: "[Models] in an assaulting unit... move following the same rules as in the Movement Phase."
BRB, page 14, Moving Through Difficult Terrain, "If a unit starts its move outside terrain, the player must declare if he wants his unit to try to enter difficult terrain as part of their move. If he chooses not to, the unit moves as normal but may not enter difficult terrain."

Simply put, the choice to enter the difficult terrain (or not) is usually* up to the controlling player.

But what about BRB page 34, Moving Assaulting Units, "Assaulting units must attempt to engage as many opposing models as possible"?
Well, the counter is BRB page 34, Moving Assaulting Units, "If possible, the model must move into base contact with any enemy model within reach." If no difficult terrain test has been made, then models within the terrain are not within reach. For all intents, difficult terrain is impassable unless you opt to take a difficult terrain test.

So the way the movement would look is:Then you move the closest model. At this point you have the option to take the difficult terrain test as the movement between closest to closest is in the clear. If you choose not to, your assault move would look like this:It also is worth noting that the assaulter CAN assault a unit on the edge of area terrain without penalty, so long as they can get into base to base without entering the terrain. Remember that you can move up to and be touching the terrain, just not "in" it.
Basically, someone who wants to get the benefit of terrain had best ensure that ALL of the unit is in the terrain.

*Now why did I say "usually" up to the controlling player? Because it's not always. The specific steps of moving assaulters is that you move the closest by the shortest route, check difficult/dangerous terrain based on that route, see if the model made it and THEN move everyone else. For example:So if the closest to closest move goes through difficult/dangerous terrain, you MUST roll the check. Otherwise, the choice is up to you.

Cheers and hope this has given you some evil ideas. Check back again in a day or so and I promise I'll have the banner contest up and running!

Oh, and for one other thing, it looks like my guest articles on Space Wolf Vehicles have posted over at Space Wolves. Go have a look and tell me how I'm wrong. :-p

***Main image undoubtedly copyright Star Trek or something and will be removed if requested. The rest are crappy Powerpoints as I don't have Vassal 40k when posting from "work"***