Is this true?

[Danial]

I was reading over the Alien pages of the wiki and it states in the Sectopod and Cyberdisc pages that because they take up 4 squares, they receive 4x the damage from HE. Is that true? I would have thought that each segment would be calculated independently, and if one segment reached 0 Health, then the whole unit would die. I didn't realise each segment's damage was cumulative.

[Bomb Bloke]

It's UnitPos vs UnitRef. The former handles the position and status of units in the field (stuff like whether a unit is alive), the later handles their stats (stuff like their health).

 

Now, a large unit is made up of four small units tacked together (four UnitPos records), each referring to the same UnitRef record. That is to say, it's four units sharing the same health bar.

 

Never really thought about it, but I suppose this should mean an explosive can potentially do a lot of damage to the big boys. Keep in mind that each segment will take a different amount of damage (depending on where they are in relation to the center of the blast and how the four dice rolls come out), so 4x is a bit of an approximation.

[NKF]

Large units are made up of one unit with 3 attached dummy sections that reference the same set of stats that belong to the first segment. Thus, if each segment is damaged independantly in an explosion, damage is done to the stats attached to the first segment. So, the same unit experiences HE damage four times. Granted, it's not truly 4x the damage due to damage dropoff from the explosion centre.

 

- NKF

[Danial]

So if one corner of a Cyberdisc is at GZ 100, the other 3 will be at 90, making the total health damage 370, is that correct? (ignoring modifiers that is)

[Zombie]

Approximately, yes. Armor also plays a big role as well which can be rather significant with the terror units since their under armor is quite high. A direct hit at one segment with HE will damage all 4 segments of shared under armor due to the way it is calculated. I haven't figured out yet if damage to each segment is calculated as a group and then armor is applied or if each segment is calculated separately and applied one-by-one to armor. I believe it is the former, but it needs testing.

 

- Zombie

[NKF]

Hmm.

 

I suppose one way to check would be to set the centre of the explosion one tile away from any of the segments, so that you can get directional damage done to the outer segments.

 

That way we can see if multiple sections get damaged independantly, or if it's just the one. If it's just the one, if more armour loss is observed than is expected for a single attack, then it's most probably combined.

 

- NKF

[Bomb Bloke]

For what it's worth, it'd be a lot harder code-wise to process the segments as a group then it would be to do them as the blast comes to them.

[zaimoni]

For what it's worth, it'd be a lot harder code-wise to process the segments as a group then it would be to do them as the blast comes to them.

It should go without saying that the armor stats are in UNITREF. Has anyone already fact-checked how armor damage works for large units?

[zaimoni]

(have a Floater terror mission going at the moment...no real chance to use explosives yet)

 

No fancy processing to guess facing, at least. When firing from the right of a Reaper, right armor is damaged even if it's the left front quadrant you hit.

[Zombie]

I just put together a great little testing scenario for myself. Since the only 2x2 terror unit with 100% susceptibility to high explosives is the Reaper, I got lucky when I happened to run across a natural Floater terror mission at the end of the first month. That's great news because I didn't have to edit craft.dat to get the right race to show up. Even better news? I used my modified Map set (found here in our files section) so that all landscape types are completely flat and level and without any objects or buildings to get in the way. Neat stuff to say the least.

 

Since I was running on beginner skill level I was only getting about 2-4 Reapers though. So that meant a quick trip to the executable to edit a minimum of at least 10 terror units for each type (there are 2 types). That meant a minimum of 20 Reapers would show up. When my men reached the terror site, I had my uber-Psi testing squad MC all the aliens on the map. I only found 7 Reapers (no civilians though). However, when I looked in Unitref.dat, there were 14 Reapers listed (no civies). I guess that proves once again that X-COM tanks spawn first, then come X-COM soldiers, then the alien rank loadout in the executable. Terror units spawn last because they are always last in the executable list. Finally civilians spawn. In this case, the excess of large terror units clogged the unit list and prevented civilians from showing up. Didn't muck with spawn points for my custom map set, so I suspect there were not enough large spawn points allocated for each module too. I suppose it didn't help that I brought along 16 men either, but 7 Reapers is plenty for testing.

 

Anyhow, I'm going to use a normal Grenade for the Armor/explosive trials. It was a lesson I learned the hard way when testing with HE shells fired from a gun in the Damage Modifier trials way back. Shells can stray when base chance to hit (combination of soldier FA and weapon accuracy) is less than 100. Also, a static blast makes easy to control which quadrant will ultimately get hit. Not that it matters much as only under armor is affected from HE if a direct hit is scored. All I have left to do is edit the blast strength of the grenade so there isn't any overlap, run a few trials and then automate the whole process. With 7 units taking a hit each round, I'll get some great numbers in only about 200 trials. (See the pic below with all the Reapers lined up in a row). And don't worry, I'll let the Reapers go back to full alien status before using them as test subjects.

 

 

- Zombie

[NKF]

I gave the offset blast point a go to see how armour was affected. Indeed, different armour sections were damaged.

 

I was less fortunate in that I was running my test against one of own tracked HWPs. They're practically immune to standard grenades, and it took me 3 alien grenades in succession to even put a dent in it. This time it got crippled half way and both under armour as well as rear armour were damaged.

 

This means that damage is dealt independantly to the various sections (easiest way to go about it, really). So armour has to protect (and get damaged - if breached) for each quarter that gets caught in the blast. In a way, every subsequent breaching hit after the first reduces the impact of the 10 point damage dropoff.

 

By the way, the way which section gets hit on a large unit is easy enough and requires no fancy processing. Just imagine all four segments as if it were a single unit. If the left side gets hit on any of the quarters (say from an explosion), left armour is used/damaged. Something I noticed when I was meddling with the unit flags and somehow turned one of my soldiers into a large unit and had four units marching about in perfect sync.

 

- NKF

[Zombie]

But... but... but, what's this about different armor sections damaged? If a blast connects with a 2x2 unit, only the under armor should ever be affected. Blast propagation always affects under armor out to GZ+1 so all quarters take damage to that section of armor no matter what. I can't stress that enough.

 

I ran about 50 trials with various blast strengths from 10-50 just now and in all cases under armor was the only area which saw a drop. No other areas ever changed. Since blast theory matches the data, we cannot draw any other conclusion if an explosion happens directly under one section of a 2x2 unit.

 

Now, assuming you are letting the explosion happen one tile out from the unit, then yes, different sections will be damaged. One section will always be under armor (GZ+1) while the other sections will be the armor sections facing the blast (GZ+2). (I have no idea what happens if the blast was equidistant from the other two facing sides [think: perfect 45 degree angle], it depends if the game handles the alien as a unified unit or as a group but if my understanding is correct only one other armor area would ever be damaged). This kind of a test really doesn't prove anything except that blast theory still holds.

 

- Zombie

[NKF]

It was offset 1 tile away - wouldn't make much of a difference if it was offset inside the large unit

 

My test was done at a 45 degree angle (rear left), so under and rear armour was struck. I think some left armour should've been removed too, but perhaps it did not do enough damage to breach.

 

I wanted to see if the game would only remove armour from one facing or from multiple facings. Just to see if it the unit is treated as a whole when deducting armour or if the parts are treated separately. Nothing terribly exciting.

 

- NKF