Both would be considered attacking.

All moving units will be engaging in attacking. Only standing still units will be defending.

not right

each unit is able to attack, but do not need to. Only if you give attack order an attacked unit fights back.

Each unit which attacks has one strike per hour, beginning with the moment the attack starts.
The attacked unit answers in this case with its defense value, so the attacker can be damaged as well.

If the defender gives attack order too, the defender unit also has one strike per hour starting with the first strike when order is given. In this strike the attacker uses his defense value against the incoming strike.

If you are a defender with a high defense unit such as flak or antitank units its is not wise to give an attack order. Let the attacker unit try to attack you and dont hit back. Your defense value is much stronger than your attack value.

Therefore with a mixed stack that contains at least one tank, it would be wise to split the tank(s) from the stack and issue an individual attack order to it/them? Assuming the attacking stack does not contain AT, of course.

Indeed it would be wise to split big groups in any case into small groups with a maximum of six units of the same kind in it because of the efficiency.
You cant take a look of the efficiency, hitpoints and so on by clicking the troop info.

Another advantage is that the attacker only can choose one single group as a target

The exception being aircraft units on patrol, which update every 15 minutes.

The practical implication of Arbales' basic truth above is that formations that are composed largely of infantry, anti-tank, and tank destroyer units usually do better on defense, but that also depends on the composition of the attacking formation.

As a practical matter, artillery units should never be on your front lines. Artillery -- both conventional towed artillery and self-propelled artillery units -- are far weaker on defense than when attacking, and conventional towed artillery only have 5 hit points per unit.

good point.
Never bring artillery into melee. Seperate all artillery units from the other before attacking one target and give a seperate attack order to the artillery unit. It will stop at bombardment range while the other units continue walking to the target.

Every time you can take a look to enemy units DO looking at them, read the level and detailed information of the units you are going to attack. Especially read the attack and defense values of them and the efficiency. Choose the perfect mix from all of your incoming units which deal the best damage by minimum vulnerability

I don't believe in "perfectly mixed" stacks because it usually pays to have more of everything, even if the particular unit type is operating somewhat below maximum efficiency, if for no other reason than the first units of that type to get killed drop the unit type below its desired offensive and defensive values within the stack. The perfect example of this is having extra destroyer squadrons to protect your capital ships; I will base my warship battle groups on the efficiency of the capital ships, i.e., only three or four battleships per battle group, but I generally like to have a minimum of 4 destroyer squadrons per capital ship in that battle group stack. The DDs serve three key functions of protecting the BBs (and CVs, if present) from submarine and air attacks, and also as damage soakers from naval gunfire. I must be doing something right -- to date, I have never lost a capital ship in battle, and I've sunk more than my share.

The other argument against large "perfectly mixed" stacks is nuclear missiles; I always do the rocket and nuclear research, even if I have to use some gold to work it into the research cycle. But I will hide the fact that I have nuclear missile capability by not completing my reactors (leaving the final hour of construction undone) until I need them, and I am rarely the first person to build the conventional rockets, either, thus enemies assume I have no rockets let alone nuclear missiles. It's a great way to sucker your over-confident enemies to come at you with those big, "perfectly mixed" stacks. And nothing deflates a big-time gold-spammer like watching 50 or 60 of his gold-spammed armor units disappear instanly with a couple of nuclear missile hits, followed by tactical bomber strikes to finish off any survivors.

Oh, and I have never built a nuclear bomber (although I have captured a couple in mid-production). If I'm going to invest that much time and effort in doing the research, and building the required reactors and L3 air bases, as well as the L5 industrial complexes to produce the nukes quickly, I don't want a nuclear bomber that is easy to defeat with either AA or interceptors. I learned that lesson in my first game, when my primary ally lost two nuclear bombers to AA fire. Huge disappointment.

I obviously missed something when reading about the State Based Efficiency as I came away with no stack should be more than 5. Hence I am running 2 Art, 2 AA with either 1 Lt/Med Tank or 1 Inf/Jeep depending on the speed type of my Art and AA. Sometimes I go 6 to the stack. I just run these smaller stacks in column, so if the first stack comes under attack I can run the tank/Inf forward to keep the Art out of combat, and the other stacks further back stop and open fire with their Art. Seems to be working so far, Game 1 is complete with 2 & 3 in mid to late stages.

Tacs I run in stacks of 5 and use fighters to clear the air before committing to target if I suspect fighters are in play. I use the Tacs and rockets to weaken objective points in advance of the above columns.

Not the "stack," Peter, but the individual unit types within the stack. For example, the maximum efficient number of destroyer squadrons within a stack of warships is 7. Now that does NOT mean that an eighth destroyer squadron would reduce the strength of the stack; the eighth destroyer squadron does, in fact, add additional firepower to the stack, but each additional unit of that type adds a diminishing amount of firepower (it's very much like the economics concept of diminishing marginal utility or diminishing marginal returns). So, for example, if you have the choice of splitting a stack of 14 destroyer squadrons into two stacks of 7 destroyer squadrons while attacking a stack of submarines, the two stacks of 7 each will inflict more damage on the enemy submarine stack than would a single stack of 14.

Oh, and just for fun, the maximum efficient number of units of any given type of unit varies from unit type to unit type. The maximum efficient number of destroyer units is 7; for conventional submarines, it's 8; for interceptors and tactical bombers, it's 5.

But if you are going to attack an antitank stack of an enemy, and you can choose fom three tanks and three infantry, let the tanks stay back and choose the infantry, because of the kind of attack.

tanks attack with another kind of attacktype as infantry and the antitank has much lesser defense against infantry attacks than against tanks.

Okay, you are right in the case you have 60 tanks you can join the attacking infantry because the bulk strength is much bigger then.

BUT if you have 60 tanks it would be batter you attack at the same time with 10 stacks of 6 tanks each than one stack of 60 tanks

Mmmmmm mmmm mmmmm. Nuclear missile bait. Yum, yum, yum.

Kidding aside, I have found no advantage to having infantry in the stack opposing enemy armor. The infantry simply become inefficient damage soakers for your own armor. Given the choice of defending against enemy armor with 20 of your own armor units, or 20 mixed infantry and armor units, all armor is better. My answer may change if (a) you have multiple anti-tank units in your stack, and/or (b) you are defending an urban area where the enemy armor's strength and hit points are reduced by 50%.

One of my favorite COW memories was completely destroying two enemy stacks totaling 30+ infantry regiments supported by 3 or 4 armored car brigades, with half that number of light tank brigades on my side. The battles took place on an open plain, and the two allied enemies attacked my forces. It was a massacre. Terrain does matter. A lot.

Absolutely correct.

Also absolutely correct.

Anti-tank units, probably because of their low hit points (10), always work best when they are embedded in a larger stack of mixed units. Otherwise, they get killed too quickly to inflict the maximum possible damage on the enemy. The AT units also suck on offense -- if you need evidence of this, send two low-level AT units to attack an AA regiment and a supporting infantry regiment in a city, and see what happens.

Yes, but only applies to units standing in the province center (city) though. Units on a path always attack and defend, no matter if they are moving or standing still.

I am confused at the responses.

I am under the impression that non-moving land units which are attacked, use their defending skills.

If the unit is moving or given moving instruction during the battle, they then become attackers and get their own attack count-down.

I routinely set up my units to stop just before coming into contact with the enemy so that they are considered defensive when the enemy runs into my troops.

And then, there are scenarios when the enemy troops are at low health, I will then use my troops to attack the enemy instead of waiting another hour for the enemy attack to occur.

Lastly, I am under the impression that if both units are "attacking", having a count-down until their attack, they then use their attack skills instead of their defense skills.

when in battle, check the info from the units, it'll say who is attacking and who is defending or even if both are attacking

really invatry tanks and planes are attackers while miltia, aa, and at are defending artillary is special because its both but when attacking ts more ofa surpresser and whil defending its purpose isto take our armour

that's right

Assuming A starts to attack B at 9 pm
A will strike every full hour at 10pm 11pm and so on
When ever A strikes A uses attack value and own attack type (inf, armor, air, sea) B uses defens value.
In the info of A you can read is attacking B
In the info of B you can read is attacked by A

At 10:30 pm B decides to strike back by drawing the unit actively on the attacker A or with the attackbutton
B now will make a strike on A every hour at 11:30pm 0:30am 1:30am
When ever B strikes B uses attack value and own attack type (inf, armor, air, sea) A uses defens value.

In the info of A you can read is attacking B, is attacked by B
In the info of B you can read is attacking A is attacked by A

Arbales thank you for very precise information ! I'm awed, and know more now.

If B attacks back basically the fight will be more fierce, getting two fights per hour instead of inactive defending once per hour (if I understood correctly).