Damage
Or, how much damage can a weapon do to a unit with so much armour.
Formula:
damage to unit = (weapon damage * damage modifier) - armour
If the bullet does negative or zero damage, then the bullet is ignored. If the bullet does damage, then there's a chance that the armour plate that it struck will deteriorate by a few points.
That's the basic idea. Let's expand on the variables a bit.
armour: Is simply the value of the armour section the bullet hit.
damage modifier: 0.5 if the unit resists and 2.0 if the unit is weak against the weapon's damage type. I'm not sure, but there's probably also a 1.0 for units that neither resist nor are weak against the bullet type.
weapon damage: Weapon damage will be a random number between 0 and the damage level of the weapon. In reality, all weapons do half their listed damages on average (something to do with the distribution of random numbers leaning more towards the middle of the normal distribution curve).
A critical hit is therefore anything above 50% to 100% of the listed damage (or 100% to 200% for double damage, 25% - 50% for units that take half damage).
It's interesting to note that X-Com units take double damage from practically every major weapon type. I know for sure that they take double damage from AP, Plasma and laser (I tested: rifle bullets were doing up to ranges of 60 points of damage to X-Com units when they're only supposed to do 30). No wonder your units drop like flies. At least this is true for unarmoured soldiers. I'm not too sure if armour helps reduce this to normal damage.
-- NKF, Dec 18 2003, reposted by --JellyfishGreen 16:01, 21 Apr 2005 (BST)
Modifiers
Basically, everything's 100% except the following:
Vulnerable to...
Incendiary:
Reaper: 170%
High-Explosive:
Silacoid: 130%
Laser:
Sectopod: 150%
Melee:
Unarmoured Soldier: 120%
Civilian: 120%
Sectoid: 120%
Celatid: 120%
Floater: 120%
Celatid Acid Spit:
Unarmoured Soldier: 160%
Civilian: 160%
Sectoid: 160%
Celatid: 160%
Floater: 160%
Personal Armour: 110%
Resistant to...
Armour-Piercing:
Cyberdisc: 80%
Muton: 60%
Zombie: 60%
Incendiary:
Personal Armour: 80%
Chryssalid: 80%
Ethereal: 70%
Snakeman: 70%
Tanks: 40%
Power Suit: 0%
Flying Suit: 0%
Silacoid: 0%
High-Explosive:
Sectopod: 80%
Zombie: 80%
Tanks: 70%
Cyberdisc: 60%
Laser:
Zombie: 70%
Plasma:
Sectopod: 80%
Zombie: 70%
Stun:
Personal Armour: 90%
Chryssalid: 90%
Power Suit: 80%
Flying Suit: 80%
Ethereal: 80%
Zombie: 0%
Melee:
Tanks: 90%
Celatid Acid Spit:
Tanks: 40%
"I find it amusing that Celatids are vulnerable to their own spit" -- Danial
Explosive Damage to Walls and Objects
Explosive damage to objects (anything that isn't a unit) is constant; grenades will always form the same blast pattern on the same terrain. The peak damage is done at the center and falls off by 10 points per tile radius.
It's known that a Blaster Bomb is the only thing capable of blasting through a UFO outer hull (walls and roof). It does exactly 200 damage at the epicenter and only ever knocks out one tile.
When we boost the power of the humble High Explosive with a game editor we see the following:
- 190 for HE strength is not enough to bust a hull open.
- 200 is, but only one tile wide.
- 210 opens up a hole 3 tiles wide
- 220 opens up a hole 5 tiles wide.
For every 10 points of HE strength above 200, it adds 2 to the width of the hole.
- reposted from discussion, NKF/Jasonred/Zombie, strategycore forums 2005, --JellyfishGreen 02:21, 25 Aug 2005 (PDT)
Blast diameters differ according to terrain type. The table below was copied from a post by Zombie. To get radius, subtract 1 and divide by 2:
Grass,
Lawn,
Corn Dirt, Asphalt Polar
Fields, Weeds, Roads, White Snow,
Wheat Desert White Tin Tile Concrete Mars Mountain Alien
Cost E115 $/HE Weapon HE Fields Sand Shngls Roofs Roofs Walkway Sand Tundra Floors
700 15.9 AC - HE 44 7 7 5 3 1 1 0 0 0
300 6.0 Grenade 50 7 9 7 5 3 3 1 0 0
500 9.6 HC - HE 52 7 7 7 5 3 3 1 0 0
500 7.1 Prox G 70 11 13 11 9 7 7 5 0 0
600 8.0 Small R 75 9 9 9 9 7 7 5 0 0
6700 2 74.4 Alien G 90 13 13 13 13 11 11 9 3 0
900 9.0 Large R 100 13 13 13 13 13 13 11 5 1
1500 13.6 Hi Ex. 110 13 13 13 13 13 13 13 7 3
8000 3 40.0 Blaster 200 23 23 23 25 25 23 23 23 21
Where HE is the High Exposive rating for each round and:
- "White Shingles" is the roof on the gas station complex,
- "Mars Sand" is the soil on the Martian surface in Cydonia,
- "Alien Floors" is the floor of an alien base (alien ships were not checked), and
- "Concrete Walkway" is sidewalks near buildings or roads.
Buy price or manufacturing cost are also shown (part cost only; does not include labor), whether Elerium-115 is needed, and "dollars per HE" (Cost/HE).
Zombie and NKF theorize that terrain "sops up" (or absorbs) a portion of the damage. Each tile from ground-zero absorbs part of the explosion until the damage left is less than tile "armor". So, while the OSG clearly states that damage drops off by 10 per tile radius, apparently the tiles are absorbing some of the damage, as well. Any units or items on the ground directly adjacent to the edge of the blast are not damaged. Blast diamaters are always symmetrically round, unless some of the terrain is "harder" than the rest. For example, if a bomb opens up a hole in a UFO, the blast pattern outside the UFO will be a standard half circle for "outdoors" damage, but inside the UFO, there will be a smaller pattern.
Additional specifics on blast damage by Zombie can be found here and here. To be collated and added to this wiki soon.