falling back and overwatch

[Uncle Nutsy]

here's the setup:

unit 1 (say a DE archon) versus unit 2 (a blood angel tac marine). the marine just lost and was able to make it's falling back move. Now, other than that tac marine being able to shoot back in a 'puleeeze jebus halp me!' manner, can an uninvolved unit (such as a dreadnought for example) snap shot that archon?

[EnglishInquisition]

Not clear on what your scenario is describing?
If the Marines are falling back from combat from the Archon, then the Overwatch subphase has passed.
If they are falling back from shooting by the Archon, then the Archon must assault the Marines therefore the Dreadnought wouldn't be able to overwatch as it wouldn't be involved in the assault. If the Archon is in a unit that is then trying to multi-assault and the Dreadnought is being assaulted then it can overwatch (although I have a feeling that Walkers aren't allowed to overwatch anyway, but the principle stands if the Dreadnought was another infantry unit).

[Aramel]

Yes walkers and MC can overwatch.

[DarkLink]

But only if they're being assaulted. A third party can't shoot into an assault move they're not involved in.

[Uncle Nutsy]

no, this is after the assault has happened, when wounds are tallied, and morale tests made. during sweeping advance.

[Tynskel]

there is no overwatch during sweeping advance.

Overwatch is a specific step within the Assault Phase. It occurs when the attacking player has declared a charge, but before moves have been made.

[Uncle Nutsy]

read page 30, under "falling back and shooting".

[EnglishInquisition]

If the SM are falling back and are assaulted then-
They take a morale check to regroup at full Ld
If they fail they auto-die and removed from game, no assault takes place.
If they pass, they overwatch and fight as normal.
A bystander Dreadnought/unit cannot overwatch fire unless they are included in the assault.

All on page 31.