In this game we've been getting a lot of "attacked x with 0 units" on our artillery attacks:

http://www.wargear.net/games/log/74277

Is this a board design issue, or are artillery attacks broken in general?  Or is there some aspect to the mechanics that I'm misunderstanding?

Having the same issue in another game. Anybody know what it means?

http://www.wargear.net/games/player/74490

This means that the player was attacking via an artillery border and the target territory has already been reduced to the minimum allowable number of units (either 0 or 1 depending on whether abandon is on). An actual attack is not permitted because this could result in the target territory being reduced to less than 0 / 1 units which is not permitted over artillery borders.

This counts as an attack in terms of the SimulGear order of play but there is no actual attack made.

On the other hand, in some cases artillery attacks are reducing the defending territory to 0 armies (which I thought was the intended behavior).  So one of these two cases is incorrect.

If you look at the history of that game, you will see both cases where artillery attacks cause a territory to be abandoned, as well as cases where attacks were made with 0 units when the defender had armies defending.

Yea, it is happening in a game I have with you, BlackDog, right now.  I have plenty of attacking armies and the way the game works you can generally bring a defender to 0 with artillery. But sometimes it will attack with 0. Perhaps Nygma has to make some changes.

Tanks is not abandon, you must leave 1 unit behind, which means 1 is the minimum a territory can be brought to.  For the same reason that artillery borders don't show up in Turn Based abandon games when there are 0 units in the territory, your attack does nothing when attacking a territory with 1 unit left...  The game does not allow abandonment, so 1 unit is the best you can do.  In tanks you want to then use the adjacent tank to take over what you've brought to the minimum.

So it looks like the board is working correctly now, but was not earlier in this same game?

In the turn we just took, one of my tanks was reduced to 0 by an artillery attack.  I believe it has to do with the number of units on the defending territory.  In cases where more than one unit defends, it can be knocked to 0.  In cases with only 1 unit, the map realizes it should not be attacked and it is safe?

Yes this is the correct behavior in SimulGear games - the alternative is that the defender has to be gifted a unit back if they go below one unit which was deemed to not be the preferred solution.

Is there a way to set it so that you can only take the defense down to 0 if it has multiple units to begin with? That way it will be the same for attacking multiple defenders as it is for attacking a single defender?

Not at the moment... this might need revisiting though. It would need to be a new rule as this might affect designed in behavior for certain boards.

If I am understanding this correctly, then I think this is a bug.  Let me see if this is correct:
  When attacking from A to B with an artillery border (no abandonment),
    if B has a single unit, then the attack counts as an attack, but nothing happens.
    if B has more than 1 unit, then the attack carries out normally possible taking the territory down to zero.

One of these two cases should not happen, either artillery attacks should take a continent down to at least 1 army or it should be able to take it down to zero armies.

Is this the same way for turn based, attacking 1 unit via artillery is not allowed, but attacking 2 is with the possibility of killing all units?  Kjeld's Total Wargear does not seem to function this way, but there are capitals at the end of the artillery border.

The correct solution to me seems that either
  1) an artillery border should be able to be defended by one unit less than is there to capture (i.e. cannot go below one unit after the attack) or
  2) an artillery border can kill all units in the defending territory (just no capture is made with or without abandonment).  With abandonment, territory is held by original player, without revert to neutral.

I am not an expert on this feature, but I don't believe that implementing option (1) would effect any board which is currently released as this is how I thought artillery borders worked.  Does anyone know of a board?  Option 2 would effect boards that are turn based, but I don't think it would effect any SimulGear Boards since killing all units without capturing is possible normally.

Second question:  Is it stated correctly above that artillery attacks happened even though there were zero units to preform the attack (this is certainly a bug)?

What is happening in the Tanks map is this:

-when you attack from A to B (A having say 5 units and B having 1), it counts as your turn in that round, but says that you attacked with 0 units.

-when you attack from A to B (A having 5 and B having 3), it will attack and can bring the territory to 0 and neutralize it.

So to answer your second question, it is not performing an attack even though there are 0 units available, but rather it is saying that there are 0 units attacking when you attempt to artillery against a Defender with 1 unit.

IMO, I think bringing a territory to 0 and neutralizing it is the better option, at least for the Tanks board, but as long as something gets changed so it is consistent either way, then I'm happy.

Alpha wrote:

Is this the same way for turn based, attacking 1 unit via artillery is not allowed, but attacking 2 is with the possibility of killing all units?

If attacking via an Artillery Border (with Abandon Off) to a territory that has 2 units , then really only 1 dice is thrown for the defender.  That way the territory will always have 1 unit left.  (If Abandon is On then takes down to 0 and the Return to Neutral Rule is used.)

Seems like this could/should be the same for SG.

As far as the Attack actually taking place, without thinking deeply, I would think it shouldn't show in History and that it should be "thrown out" as invalid, similar to if you set up an Attack order (not Attack/Fortify) to a territory, but at the time of the Attack to take place you already own that territory then that order is thrown out and the next is used in its place...at least that is what I think occurs.

I echo above.

I've updated the code to fix both these issues:

1. Artillery attacks to territories with the minimum allowed units are now discarded before being added to the execution queue 

2. Artillery attacks with abandon off can only bring a territory down to 1 unit remaining in SimulGear games (number of defending units is 1 less than the total territory unit count).

This update will go out tomorrow morning.

Thanks, Tom.