Si non potes reperire Berolini in tabula, ludens essetis non WIF.
Hey, get your stinking cursor off my face! I got nukes, you know.
The attacker can decide if a battle is a blitzkrieg or assault if they either have a) more ARM units than the defender or b) more MECH and the defender has no ARM. Of course, provided the attack is in the right sort of terrain etc.
The rules say that a division is counted as half a unit for these calculations. If the attacker is attacking a stack of infantry units (no defensive ARM, MECH or AT), would a single attacking division of MECH or ARM be "rounded up" to a full unit and thus allow the attacker to choose blitzkrieg?
Yes, a single arm or mech div in an attack against a hex with no arm, mech, or AT is enough to
call blitz choose the combat table.
Similarly, if the defender has two MECH units, would the attacker then only need a single ARM division to go for blitzkrieg?
Yes because ARM trumps any number of MECH, the attacker may choose the combat table.
In the same regard, what happens if the attacker has an ARM corps (or army) and the defender has an ARM division? Would the defending division be "rounded up" to a full corps, or would one take "the difference" of "half a unit" and let the attacker decide?
This was actually discussed recently in the WIF playtest group. I had always played that because the rule referred to "units" that one ARM corps was not greater than one ARM division and therefore the choice would be with the defender. I'd seen it ruled that way at WIFCON, too. HOWEVER - many people apparently play it the other way (i.e. wrongly IMHO!) and rule that one ARM corps is in fact more than one ARM div, and so would be able to call blitz. I think that second interpretation (one corps/army is greater than one div) is going to end up in the new version of the rules. So in short, one ARM corps attacking against one ARM div, the attacker gets to choose the combat table.