Diplomacy rule question - is this correct, or is my adjudicator bugged?

Factual Questions
1

I’m currently gamemaster in a play by email game of Diplomacy among a few buddies. The following situation has occured:

There are German armies in Gascony and Piedmont, a French army in Marseilles, a Turkish fleet in Gulf of Lyons and a Turkish army in Tuscany. Turkey and France are allied against Germany.

Germany has ordered A Pied-Mar with support from Gas.
France has ordered A Mar-Pied, and Turkey has submitted supports for this from GoL and Tus.

My adjudicator software (usually reliable, but as every software not guaranteed to be bug-free) has come to the result of A Mar moving into Pied and dislodging the German army there (and disbanding it, since there were no empty provinces for retreat around).

I’m not entirely convinced by this; there were no units bouncing A Pied out of Marseilles, and since units cannot switch provinces (A Mar-Pied, A Pied-Mar), wouldn’t this result in a stalemate, with no unit moving.

2

Oops, forgot the (albeit evident) question: Am I right, or is the software?

3

If I read your description of the situation correctly…

A Pied-Marseilles
A Gas S A Pied-Marseilles

A Marseilles-Pied
A Tuscany S A Marseilles-Pied
F GuflOfLyons S A Marseilles-Pied

So… You’re got an attack with strength with a strength of 3 and an opposing attack with a strength of 2. The result is that the army in Marseilles enters Piedmont and the army in Piedmont is dislodged.

What’s the problem?

Or is there some unit involved?

4

That should be:

some <i>OTHER</i> unit involved?

5

I don’t understand what your last sentence means, especially ‘bouncing’.
As Satyagrahi said, it’s a dislodgement by the better supported French move A Mar-Pied.

Incidentally:

  • two units can’t exchange places, but 3 (or more) can.
  • if the support of one of the Turkish units had been cut, then it would indeed be a stalemate/standoff.
6

The adjudicator is correct. A Mar -> Pie has 2 supports, and A Pie -> Mar only has 1.

What may be confusing you is usually supports for a move don’t help you defend a territory. For example, if France’s order was A Mar -> Bur with two supports and that attack failed, the Germany attack from Pie would succeed since the supports given to the French attack don’t count for defense.

However, this doesn’t apply when the two units are attacking each other’s territories. In that case the one with the higher number of supports wins.