So I played a couple of quick games tonight with my sons and we tested out 4 units of Standard Inner Sphere Battle Armour agianst a Clan Dasher.

It all ran fairly smoothly but it occured to me during the games that a Mech could conduct a Physical Attack against the Battle Armour....so I looked it up in the rules and a Mech can conduct a Physical Attack against Infantry in the same hex as it. It can do either a Thrash Attack (if it's prone) or a Kick/Stomp Attack if its standing.

So in the instance I was thinking of, if a Battle Armour unit chose to conduct a Swarm Attack on a Mech and failed, the Mech could then try and stomp on the Battle Armour unit.

Lets assume the Mech successfully stomps on the Battle Armour, how is the damage applied? Lets say it was a Daishi and it did 20 points of damage (1 point for each 5 tons for a Kick Attack). Would the 20 points be applied to a single randomly chosen Battle Armour Trooper with the excess damage lost (like a Weapon Attack), or would the excess damage transfer to the next randomly rolled trooper?

Also, does the +1 modifier for attacking Battle Armour apply to Physical Attacks or only Weapon Attacks?

The damage would be all applied to one trooper.

Attacks Against Battle Armor
When a unit attacks a battle armor unit, the attack targets the
unit as a whole, though individual troopers take the damage.
A single member of a battle armor unit cannot be the target
of an attack; the trooper damaged by a successful attack is
determined randomly. Use all standard modifiers. In addition,
all non-infantry units must modify their to-hit numbers by
+1 for attacks against battle armor units to account for the
spread-out formation and tactics of battle armor units.
On a successful attack against a battle armor unit, roll 1D6
for each Damage Value groupings to determine which battle
armored troopers are hit. Each grouping strikes a different,
randomly determined trooper. Re-roll if the unit does not have
that number of troopers or if the result indicates a trooper
destroyed in the current or a previous phase. Any excess
damage from a single damage grouping is wasted.

TW p219

Ah cool, thanks for clarifying that for me Rick, that makes a Stomp slightly less frightening

im glad that its applied that way, otherwise youd never field infantry as they just become jam under the feet of those bigger mechs