UFO destroyed!

[dchunghk]

Any idea what UFOs can be destroyed instead of shot down? I looked around but didn't find anything. How much damage over and beyond armour do you need to achieve it?

[NKF]

Generally the killing blow needs to push the UFO's hitpoints well into the negatives in order to destroy them.

 

I don't have the exact numbers, so I'll let my colleagues fill this gap in for you.

 

In general the three scouts can be easily destroyed with heavy hitting weapons like the plasma beam and fusion ball launcher. The small scout is often easily destroyed with the Avalanche or Stingray, and I think the Avalanche can do the same to the medium scout from time to time.

 

The fusion ball launcher, particularly when doubled up, may be able to destroy some of the larger UFOs as well.

 

Mmm, I might add this as a to-do note on the wiki. It's worth knowing about.

 

- NKF

[Alitorious]

I'll add: Chances for destruction seem to increase when both weapons hit at the same time. I seem to remember destroying many medium scouts with dual plasma beams, but not as many once I started using a plasma beam/laser beam combo.

I think this needs testing, though.

[Zombie]

Indeed, it sure does.

 

Some of you may know that I have dabbled in testing out basically every aspect of the game. Craft weapons didn't escape my grasp and I performed many tests on them long ago. One of the things I gleaned from those tests was that craft weapons do not always take down UFO's in a strict amount of shots. This would indicate that they pump out a range of damage values. But how is it applied? That was the big question.

 

I finally had some time a few weeks ago, so I sat down with a pen and a couple sheets of paper and drew up an outline for testing. The original plan called for testing the Small Scout against the normal cannon, but that was scrapped rather quickly due to the weapons fast rate of fire, poor accuracy and low damage potential. The Stingray seemed to be the better choice as it has the possibility to destroy and knock down the Small Scout. So I equipped an Avenger with a single Stingray Launcher and took a tally of how many times the Small Scout crash landed vs. destroyed.

 

About half-way through my testing spree I took a breather. While doing this, I remembered a passage I read in the OSG for TFTD about craft weapons. After locating it (pg. 206 if any of you have a copy), it did seem to shed some light on the subject. In a nutshell, craft weapons deal a random amount of damage between 50% and 100% of the listed value. It goes on to say that UFO damage received is dependent upon some percentages. If the damage dealt is greater than or equal to the UFO's damage cap, the craft is destroyed. If the damage dealt is between 51-99% of the UFO's damage cap, the craft crash lands. I assumed that a value of 50% or less would indicate the craft survives and continues to fight.

 

Armed with this information, I decided to hold off on the math and gather some numbers first. Out of 121 trials, 53 times the Small Scout crash landed (44%) and 68 times the Small Scout was destroyed (56%). The UFO never survived if a shot connected. Ok, now let's look at the math. (HP=HitPoints)

 

Stingray
Min Damage: 35HP
Max Damage: 70HP
Range:	  36HP

		 Small Scout
	   Survive	Grounded   Destroyed
Percents	0-50%	  51-99%	  100%+
Damage	  0-25HP	25-49HP	  50+HP
Rev.Damage   DNA	  35-49HP	 50-70HP
Range		DNA		 15		 21

Since the minumum damage a Stingray missile can inflict is 35HP, and the maximum level for the non-shot-down Small Scout is 25HP, it means that a Small Scout can never absorb a successful shot and continue to fly. It either is shot down or destroyed. That checks off. Because of the minimum 35HP of damage, we have to revise the damage range for the Small Scout being shot down. It is now 35-49HP instead of 25-49HP. The range is thus 49-35+1=15, and the probability is approximately 42%. The damage range for the Small Scout being destroyed has to be revised to 50-70HP since the Stingray has a max damage of 70. The range is thus 21 and the probability of destruction is approximately 58%. These theoretical percentages closely match the observed results (44% and 56%). Hurray! I think that about licks this problem.

 

But what about dual Stingrays? What happens then? Well, I started to run some trials and got some numbers which approximated the ones listed above for shot down vs. destroyed. Could this be right? Certainly dual launchers dish out more damage per volley than a single launcher could accomplish. Time to dive into the game files. After each successful hit to the Small Scout I saved the game and checked CRAFT.DAT for the damage to the UFO. Damage was never higher than 70 and never lower than 35! Dual launchers of the same type are thus a total waste since the damage inflicted is identical to a single shot! You are much better off equipping a craft with dissimilar weapons instead. Apparently when 2 shots happen in the same instant the game ignores one. Bummer. At least we know how to strategize craft weapon placement now.

 

With the overview accomplished, I am now in the process of drawing up a chart listing the outcome (and probabilities if applicable) of each craft weapon (single) against each UFO. Here is a short exerpt (I haven't finished them all yet) and percentages are rounded to the nearest whole number:

 

							  Small Scout
				  Grounded			Destroyed
			  Percent   Shots	 Percent	 Shots
Cannon			 100%	  3-5		 0%		 0
Laser/Stingray	  42%	   1		 58%		 1
Avalanche			0%	   0		100%		 1
Plasma Beam		  0%	   0		100%		 1
Fusion Ball		  0%	   0		100%		 1

						Medium Scout
				  Grounded			Destroyed
			  Percent   Shots	 Percent	 Shots
Cannon			  100%	11-21		0%		 0
Laser/Stingray	  100%	 2-3		 0%		 0
Avalanche		  99.8%	 1-3	   0.2%		 1
Plasma Beam		  62%	 1-2		38%		 1
Fusion Ball		  72%	  1		 28%		 1

						  Large Scout
				  Grounded			Destroyed
			  Percent   Shots	 Percent	 Shots
Cannon			  100%	13-26		0%		 0
Laser/Stingray	  100%	 2-4		 0%		 0
Avalanche		   100%	 2-3		 0%		 0
Plasma Beam		  95%	 1-2		 5%		 2
Fusion Ball		  16%	 1-2		84%		 2

Since the other UFO's have much higher damage potentials than the X-COM craft weapons can dish out, they will always be shot down and never destroyed. Simple stuff really. The only thing left to figure out is how the game handles the cutoff points for shot down/destroyed. See, I'm waging on that the game uses integer rounding to handle the damage cutoff. Let's take the Small Scout vs. Stingray Missile as an example:

 

					 Small Scout
			   Survive	Grounded   Destroyed
Percents			0-50%	  51-99%	  100%+
Damage (Normal)	 0-25HP   25.5-49.5HP   50-70HP
Damage (Integer)	0-24HP	 25-49HP	 50-70HP

See, the cutoff points can be a little bit hazy if integer rounding is in effect. Like I said, I'm betting on it playing a role, but don't know yet. The only way to test it would be to edit some craft weapon damages so the min falls directly on one of the cutoffs. Even if integer rounding isn't completely understood, the percentages I give above are within a percent or two which isn't a bad error. Still, this is an excellent start to figuring out how craft weapon damage is applied to UFO's.

 

- Zombie

[Knan]

Could be that the game calculates them in sequence. So that if one connects, and shoots down the bugger, the second one's never even considered. I think that's more probable than the 1+1=1 theory

[Zombie]

Interesting theory. So that would mean that if the UFO isn't shot down by the dual shots, more than 70pts of damage will be applied to the craft. Will have to check this ASAP. I guess I might have picked the wrong craft to test initially.

 

- Zombie

[Zombie]

Ok, so I equipped my Avenger with dual Stingray launchers the other day and hunted down a large scout. That particular UFO has plenty of damage potential to absorb (in theory) 140 pts from a single volley.

 

Mistake #1: Using anything other than aggressive attack, the UFO would pull away from the volley and not get hit.

Mistake #2: Having the launchers equipped with more than 1 shot each. Sometimes you can't tell right away if the shots connected and have to pull back, save the game, check CRAFT.DAT and then go back into the game and take another shot.

Mistake #3: Going up against a UFO with a weapon range greater than my own. Must remember to edit UFO weapon damage to 0 for future tests and increase effective range of Stingray so that less time is wasted getting into aerial combat.

Mistake #4: Having a craft weapon with accuracy less than 100%. Since some shots miss, you have to do a lot of reloading.

 

After all these mistakes, I was able to run a few tests and determine that the dual Stingray scenario does indeed pump out more than 70 pts of damage if the shots connect. However, damages greater than 70 should be showing up just as often as those less than 70. They aren't. I'm not very happy with this prospect, as it means something else is going on. One thing will solve this though: more trials. For that, I may need to call in a favor from our good friend Bomb Bloke for a CRAFT.DAT UFO damage logger.

 

- Zombie

[Tepid tasoth]

I didn't any scientific studies on this, but I think from experimenting around that dual Plasma cannons on an Avenger take less time to down supply ships than just one Plasma cannon. This wasn't by factor two, I think it's more like 1.5. Read: it takes about x seconds to down a supply ship w/ one Plasma. Two Plasmas should take out the ship in 1/2 * x seconds, but it's more like 2/3 * x seconds. Naturally, those Plasma cannons happen to miss one time or the other, so I sometimes I end up firing like 20 shots at a supply ship before it crashes.

[Zombie]

Also, if you force your ships to take an aggressive stance, the weapons will fire at a faster rate. For the Plasma Cannon, the rate of fire and/or reduction in accuracy is basically negated by the range of the weapon itself, the power and the number of shots. Who cares how long it takes to shoot a UFO down if the UFO's weapons can't match the range of yours? The only place where the rate of the Plasma Cannon would be helpful is when you are up against a Battleship and want to know how long you could survive before getting shot down yourself.

 

- Zombie

[NKF]

Tepid Tasoth: Don't forget that when you get a hit with identical weapons, it doesn't necessarily mean that both shots hit at the same time. One could've hit while the other missed, but only the hit was reported.

 

Say you had three shots, one miss and two hits. One of those hits could've been a simultaneous hit, while the other could've been a hit with only one cannon.

 

- NKF

[Zombie]

I just checked this with dual Stingrays against a Large Scout. Theoretically, the min damage with a dual Stingray setup should be 70. (Min of 35 for a single weapon x2). Damages less than 70 should therefore never happen. After a couple of reloads, the Large Scout had a damage of 47. I guess that even though the volley hit at the same time, the game still calculates the damage and hit/miss probability of each missile independently.

 

- Zombie

[Tepid tasoth]

I just checked this with dual Stingrays against a Large Scout. Theoretically, the min damage with a dual Stingray setup should be 70. (Min of 35 for a single weapon x2). Damages less than 70 should therefore never happen. After a couple of reloads, the Large Scout had a damage of 47. I guess that even though the volley hit at the same time, the game still calculates the damage and hit/miss probability of each missile independently.

 

- Zombie

 

That's odd. Maybe it uses an internal damage modifier that ranges from, say, 50%-100% damage for each hit. Looks like it's time to crank up the disassembler.

[Zombie]

That's exactly what the game does. It applies a random number between 50% and 100% of the listed damage. In the case of the Stingray, the damage range is between 35 and 70. But with 2 simultaneous shots, the game apparently calculates the shots separately instead of as a group. So not only does it do 2 rolls for damage applied, but also 2 rolls to see if a shot hit or missed. That's the only possible conclusion we can draw since damages of less than 70 were noticed for a single volley.

 

- Zombie