Explosions
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 Propagation
Blaster Bombs impart damage as follows:
Distance From
Ground Zero Damage Range
0 100 - 300
1 90 - 290
2 80 - 280
3 70 - 270
4 60 - 260
5 50 - 250
6 40 - 240
7 30 - 230
8 20 - 220
9 10 - 210
10 0 - 200
Taken from a post by Zombie. Behavior past 10 tiles is not entirely certain.
Notice how the Blaster Bomb is rated at 200 HE damage, and does that - but on average at ground zero. Then the range decreases by 10 per tile away from GZ.
Another way to view damage is relative to its edge (HPs=Health Point damage):
DFE HE MinHPs AveHPs MaxHPs N
1 Gren 0 1.27 5 15
AC-HE 0 2.50 8 10
HC-HE 2 7.90 22 10
SR 8 23.33 42 15
LR 10 24.80 48 15
BB 37 79.44 125 27
2 Gren 1 11.60 20 15
AC-HE 4 12.10 21 10
HC-HE 7 21.10 37 10
SR 12 33.60 57 15
LR 15 36.60 60 15
3 Gren 5 18.47 34 15
SR 17 43.40 70 15
LR 20 47.12 73 17
4 LR 30 60.50 91 2
5 LR 30 56.50 83 2
Where "DFE" equals Distance From Edge (1 is just inside edge of blast radius). The numbers are for Muton Soldiers (armor=10, max Health Points=125) not hit through their Under Armor, in Desert terrain.
Here we see that standard Grenades do very little damage at their edge, but Blaster Bombs are still doing tons and able to kill massive Mutons even there. (The edge for BBs was 13 tiles from GZ for the above.) The numbers also support the idea that BBs continue to decrease by 10; extending the Blast Propagation table to 13 gives 0-170; minus 10 for Muton armor leaves a max of 160; half of that (80) was seen, on average.
Zombie has posted a detailed discussion of the mathematics for blast propagation here.
Ground Zero Effect
Units at ground zero (center of blast) and the eight adjacent tiles receive damage through their Under Armor. All others receive damage to the side facing ground zero.
This is true regardless of whether using thrown items (grenades, Hi-Ex) or shot/launched explosives (AC-HE, HC-HE, Rockets, Blaster).
Susceptibility
Critters have the following susceptibility or resistance modifiers to explosive damage:
Silacoid 130% Sectopod 80% Zombie 80% Tanks 70% Cyberdisc 60%
So Silacoids are more susceptible, presumably because they are close to the ground.
Blast Diameters
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 Mtn. Alien
Cost $/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+2E 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+3E 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 ("+E"), and "Dollars per HE" (Cost/HE).
For the stun bomb, see here.
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.
Terrain tile properties (Armor, HE Block, etc.) can be readily seen in DaiShiva's excellent MapView program. Caution: You must install the extensive MicroSoft .NET platform to use MapView; see DaiShiva's site.
Blaster Bomb Pattern
See Also
Additional specifics on blast damage by Zombie can be found here and here. To be collated and added to this wiki soon.