Ground units and auto cannon

[ExChairman (OP)]

Is auto cannon a "all target" weapon? Anti vehicle and anti personell?

[DFNewb]

Seems like it's a jack of all trades master of none sort of thing.

[Father Tim]

Is auto cannan a "all target" weapon? Anti vehicle and anti personell?

Everything is an 'all target' weapon.  There's nothing you can't fire at any ground unit, and whether or not this specific unit is a 'good' choice has a dozen variables.  Not to mention the math depends heavily not only on your own tech & design, but your opponents' as well.

[smoelf]

Seems like it's a jack of all trades master of none sort of thing.

That's also how I see it. It's a kind of all-purpose weapon. It has fewer shots than anti-personnel, so it will be less effective against infantry units, but more effective than anti-vehicle because it has more shots. Against vehicles however, it will be less effective than anti-vehicle because it has lower damage and penetration, but more effective that anti-personnel, because it has more penetration and damage and at least a few shots to attempt to penetrate.

I would be curious to see what would be more effective. Assume equal tonnage: Auto-cannon or combination of anti-vehicle and anti-personnel.

[Alsadius]

I've done the math, and the AC is definitely on the weak side. Not unplayable, but it's clearly weaker than most other choices. For example, compare HAC to HB. Both get three shots, the HB is x2/x6 while the HAC is x5/x2, and the HB is 60 tons to the HB's 72 tons. And all units except some weird infantry builds have HP>=armour, so damage is more valuable than AP for killing units. On top of that, the HB is a bombardment unit, so it doesn't even need to be on the front lines to fight, while the HAC does.

The one real benefit to autocannons I can see is that low damage = low collateral damage. So if you want to invade a valuable planet and not wreck it, AC-equipped units can be your friend.

[Pedroig]

For the most part Autocannons are good for one size down on the type chart.

Medium Autocannon is good against Light Vehicles, Power Armour Infantry, or Medium Static.
Heavy Autocannon is good against Medium Vehicles etc.

Bombardment weapons are all good against Infantry, or one size less of Static Armour.  Only Heavy Bombardment can effect even Light Vehicles.

IIRC. if Armour > Penetration then ZERO damage is taken by the target.

[smoelf]

I'm not sure it makes sense to compare HAC with HB. As you say they are used in different field positions, so you won't really (at least I think) be asked to make the decision to equip your troops with either HAC or HB, but between HAC or CSAP or AV. If comparing equal tonnage (48) you have MAC with three shots x3/x2 and HAV with one shot x6/x6. The MAC still looks inferior, but the HAV can still only shoot at one target each turn, while the MAC can shoot at three, which could make the difference if your are fighting a number-strong infantry unit.

A final point to your comparison. HB in support/rear echelon fires in a phase that happens after the frontlines have completed their attacks, so their is a risk that the enemy's frontline HAC has done irreperable damage before you HB can take them out.

But I think it will take some actual combat to determine properly, since there seems to be too many variables to compare single elements.

[DFNewb]

For the most part Autocannons are good for one size down on the type chart.

Medium Autocannon is good against Light Vehicles, Power Armour Infantry, or Medium Static.
Heavy Autocannon is good against Medium Vehicles etc.

Bombardment weapons are all good against Infantry, or one size less of Static Armour.  Only Heavy Bombardment can effect even Light Vehicles.

IIRC. if Armour > Penetration then ZERO damage is taken by the target.

That's wrong. AP and armor work the exact same way as HP and damage AFAIK from:

If a hit is scored, the armour-piercing (AP) value of the weapon is checked against the armour of the target. If AP is equal or greater than armour, the shot has penetrated. If AP is less than armour, the percentage chance to penetrate armour is (AP / Armour)^2.
If the shot penetrates armour, the percentage chance of destroying the target is equal to (Weapon Damage / Target Hit Points)^2.

[Pedroig]

For the most part Autocannons are good for one size down on the type chart.

Medium Autocannon is good against Light Vehicles, Power Armour Infantry, or Medium Static.
Heavy Autocannon is good against Medium Vehicles etc.

Bombardment weapons are all good against Infantry, or one size less of Static Armour.  Only Heavy Bombardment can effect even Light Vehicles.

IIRC. if Armour > Penetration then ZERO damage is taken by the target.

That's wrong. AP and armor work the exact same way as HP and damage AFAIK from:

If a hit is scored, the armour-piercing (AP) value of the weapon is checked against the armour of the target. If AP is equal or greater than armour, the shot has penetrated. If AP is less than armour, the percentage chance to penetrate armour is (AP / Armour)^2.
If the shot penetrates armour, the percentage chance of destroying the target is equal to (Weapon Damage / Target Hit Points)^2.

OK, so has a chance of not penetrating the armour.  AP of 2 hitting Armour 4 is a 25% chance of penetration.  Appreciate the correction.

[Garfunkel]

AC is best for Light Vehicles that operate alone - for example, GeoSurvey or XenoArchaeology protection unit.

This is because light vehicles only have 1 component slot. Medium+ vehicles have 2, 3 or 4 component slots. So for a Medium Vehicle, you can make it use MAV and HCAP so that it can counter effectively both hard and soft targets. For a Super-Heavy vehicle, you might want to hedge your best and put HAC alongside SHAV and HCAP. For an Ultra-Heavy Vehicle, 2xSHAV and 2xHCAP is the best combination.

And also, if your formation has multiple types of units in it, then AC is again less useful, though it still has its niche - if you build a formation with armoured infantry (many), light vehicles (some) and medium+ vehicles (few) to create a combined arms force on the cheap, then AC on the light vehicles complements the others fairly well.

If you know your enemy composition, then tailoring your force for either mopping up infantry or busting armour is always better than using AC. If you want to see the math, look at the Ground Combat thread in the Development forum, people calculated it there.

Note that this assumes equal weapon/armour tech levels. If your weapons are higher tech than their armour, then AC becomes stronger. If your weapons are lower-tech than their armour, then AC becomes weaker.

[DFNewb]

AC is best for Light Vehicles that operate alone - for example, GeoSurvey or XenoArchaeology protection unit.

This is because light vehicles only have 1 component slot. Medium+ vehicles have 2, 3 or 4 component slots. So for a Medium Vehicle, you can make it use MAV and HCAP so that it can counter effectively both hard and soft targets. For a Super-Heavy vehicle, you might want to hedge your best and put HAC alongside SHAV and HCAP. For an Ultra-Heavy Vehicle, 2xSHAV and 2xHCAP is the best combination.

And also, if your formation has multiple types of units in it, then AC is again less useful, though it still has its niche - if you build a formation with armoured infantry (many), light vehicles (some) and medium+ vehicles (few) to create a combined arms force on the cheap, then AC on the light vehicles complements the others fairly well.

If you know your enemy composition, then tailoring your force for either mopping up infantry or busting armour is always better than using AC. If you want to see the math, look at the Ground Combat thread in the Development forum, people calculated it there.

Note that this assumes equal weapon/armour tech levels. If your weapons are higher tech than their armour, then AC becomes stronger. If your weapons are lower-tech than their armour, then AC becomes weaker.

This is 1 thing I noticed mathematically too. AC is more consistent against lower tech enemies and would be ideal to use against them to preserve as much as their infrastructure as possible.