I always thought that in this situation the support would be cut, but your unit cutting the support wouldn't be able to hold against the original attacking unit. I guess I was wrong.

No, you are correct, I was waiting for kestas to get back and tell us if this was a bug. It seems very much like it is.

I have a similar bug, whereby the Gamesmaster gave the following results:

Autumn 1910, Diplomacy: Your army at Tyrolia was attacked by the army at Bohemia, but sucessfully defended.

YET

Autumn 1910, Diplomacy: Your army at Silesia sucessfully defeated the army and moved into Bohemia.

Therefore, how could Bohemia have attacked Tyrolia in the first place - shouldn't it have been forced to defend against Silesia (and lost)?

No, that is 100% right, the Bohemia army is still able to attack. You cant stop an attack, only support moves.

Regarding the original post, sometimes the Gamemaster text is a bit misleading even when the adjudication of moves is done correctly. (ex. sometimes it claims a "stalemate" when in reality another country manages to capture a territory you are also attacking). I don't know if this is the case here, can you tell if the support was actually cut or did the gamemaster just report it incorrectly?

Stormwolf - So am I wrong in believing "if a unit is being attacked it has to defend itself"?

Yup, a unit being attacked is only forced to defend itself if it is doing anything other than moving at the moment. If the unit attacked, is also attacking, the effects of it's attack are still felt, i.e. cuts off support, or conquers a territory, unless that effect would be to cut off the support of the unit that is attacking it.

Riiiiiiiiiiiiiiiight - thanks for the clarification! :)

Can you provide the quote from the rules? I was surprised to learn that a unit can attack another territory and cut any support it is giving, even if that unit is itself being overwhelmed and forced to retreat.

"That unit" being the unit that is cutting support even though it must retreat.

From the rulebook: "A unit being dislodged by one provice can still cut support in another. Just as a unit being dislodged by one province can still cause a standoff in another, a unit still manages to cut support even if it is dislodged."

The example given in the rules:
Germany: A Berlin holds, A Munich -> Silesia
Russia: A Prussia -> Berlin, A Silesia supp Pru->Berlin, A Boh-> Munich, A Tyr supp Boh-> Munich.
Result: "Even though the German army in Munich is dislodged by a Russian attack, it is still able to cut the support of teh Russian Army in Silesia. This prevents the Russian army in Prussia from entering Berlin"

I think the phrase of a unit being "forced to defend itself" is misleading. If a country is attacked then whatever support it may be lending is cut. No other type of action is prevented.

Thanks dangermouse. I thought it was a php anomaly and didn't remember it from the rules.

Think of it in terms of a real armies, but in a theoretical world where EVERY order is started simultaneously. Unit A launches an attack on another (i.e some of the troops cross the border into a neighboring territory and fire upon some troops in Unit B1) while a another unit (B2) launches an attack on the territory of Unit A (initially opposed by other troops within Unit A that have yet to join their comrades into territory B1).

So the commander of Unit B1 learns that he is being attacked by A, so he sadly informs the commander of unit B3 that he will be unable to sustain effective support (i.e. keep lending troops), since he must now divert most of his troops to deal with Unit A's attack, or risk being overrun.

Meanwhile, B2's attack on A has the support of B4 (i.e the attacking troops decisively outnumber the defenders), so A cannot hold. Assuming his attack on B1 is repulsed (as it always will be if the defenders are not outnumbered), then A must retreat to some undefended place.

But B1's support was already withdrawn from B4.

It's the simultaneity of the moves that gets confusing in this game and dangermouse's example confuses me further!

Isn't the relevant point here the special case where an army tries to cut support from an army which is attacking it. In this case (and only this case) the support is not cut because no unit can have an effect on the territory which is dislodging it (directly or indirectly).