Destroying Terrain
Most terrain features found on the battlescape can, with sufficient firepower, be destroyed. UFO outer hulls can be breached with a Blaster Bomb, inner UFO hulls can sometimes be breached by a Heavy Plasma, and weaker structures can be destroyed by more conventional weaponry, such as Grenades or even sometimes Rifles.
Damage vs. terrain
The general rule is that explosions will do a fixed 50% of their rated damage to a terrain feature, and projectile/beam weapons will do between 25% and 75% of their rated damage. The 50% damage for explosions is at the center of the explosion; damage will decrease by a constant amount the further away from the center you go.
If the damage dealt exceeds the terrain's damage rating (or "armor"), the terrain will be breached or even destroyed. If the damage is less than the terrain's damage rating, the terrain will be completely unharmed. See Explosions#Tile Characteristics for a table detailing several terrain types and their damage ratings.
UFO walls
The outer hull of a UFO has a damage rating of 100 points: as a result of this, only Blaster Bombs (Damage = 200) can breach them. Inner hulls and doors have a damage rating of 80 points. Heavy Plasmas, with a base damage of 115, can do between 28.75 and 86.25 points of damage to terrain. 6.25 values out of a range of 57.5 possible values (6.25 / 57.5) is 0.1087, which would mean Heavy Plasma shots will breach inner UFO walls 10.87% of the time (provided the random distribution of damage values is uniform -- this has not yet been tested). Three Heavy Plasma shots have a 29% chance of breaching a UFO wall, and even a full clip (35 shots) has a 1.78% chance of failing to break through.
Tank/Laser Cannon and Hovertank/Plasma both have a base damage of 110, which translates to a range of 27.5 to 82.5 against terrain objects. (2.5 / 55) is 0.0455, so these tanks should be able to breach inner UFO walls 4.55% of the time.
The Hovertank/Launcher's fusion ball munition has an explosive damage of 140. 50% of 140 is 70, which means a Launcher tank can never breach inner UFO walls.
Certain inner UFO walls and doors are more durable than the average inner wall. These so-called "security walls" have a damage rating of 100, like UFO outer walls, and can only be breached with the use of a Blaster Bomb. Security walls have a smooth, unsegmented appearance, with several bands running along the top. Security doors are darker than normal UFO doors and do not have a line running down their centers. The upper level of Battleships are constructed solely with security walls, although security doors are only used to enclose the central lift. See image below.
Terrain structures
These figures were researched using the MCDEdit program.
UFO structures
| Terrain Object | Damage Rating |
| Outer Wall/Door | 100 |
| Inner Wall/Door | 80 |
| Security Wall/Door | 100 |
| UFO Power Source | 50 |
| Elerium-115* | 20 |
| Blue Chair | 60 |
| Navigation Console (wall) | 40 |
| Navigation Table (octagonal) | 15 |
| Round Fuel Pod | 20 |
| Oblong Fuel Pod | 30 |
| Flashing Wall (Alien Entertainment?) | 60 |
* Do not use explosive munitions near a UFO Power Source if you wish to collect the Elerium contained within it.
X-COM Craft structures
| Terrain Object | Damage Rating |
| All surfaces | 255 |
X-COM craft are meant to be indestructible (thank goodness!)... but see Explosions#Mile-High_Madness
Alien base structures
| Terrain Object | Damage Rating |
| Dirt Wall (surface) | 100 |
| Dirt Wall (interior) | 100 |
| Metal Wall | 80 |
| Windowed Wall | 100 |
| Display Cases | 10 |
| 4-space Vats | 60 |
| Other 1-space Vats | 30 |
| Command Center Table (octagonal) | 15 |
| Alien Plants | 5-40* |
* Green ones are 5-14, more colorful ones 20-40 depending on size
X-COM base structures
| Terrain Object | Damage Rating |
| Wall | 80 |
| Dirt Wall (interior) | 60 |
| Door | 50 |
| Hangar/Access Lift Door | 75 |
| Fuel Drum | 12 |
| Missile | 20 |
Farm structures
| Terrain Object | Damage Rating |
| Wooden Wall | 12 |
| Door | 12 |
| Brick Wall | 25 |
| Stairway(lower) | 16 |
| Stairway(upper) | 20 |
| Wheat | 6 |
| Flowers | 8 |
| Vegetables | 10 |
| Apple Tree | 16 |
| Normal Tree | 22 |
| Damaged Tree | 15 |
| Stone Wall | 25 |
| Hedge | 12 |
| Fence | 11 |
Forest structures
| Terrain Object | Damage Rating |
| Trees/Logs (various) | 13-18 |
| Large Tree (trunk) | 24 |
| Large Tree (branches) | 18 |
| Bushes | 12 |
| Hill | 30 |
Urban structures
| Terrain Object | Damage Rating |
| Grey Brick Wall | 25 |
| White Wood Wall | 14 |
| White/Blue Doors | 12 |
| Yellow Walls (not used?) | 25 |
| Beige Warehouse Wall | 30 |
| Crates | 20 |
| Stairway | 25 |
| Green Door | 30 |
| Smooth Grey Wall | 30 |
| Glass Door | 15 |
| Misc. Retail Objects | 5-16 |
| Misc. Furniture | 4-22 |
| White Picket Fence | 8 |
| Grey Metal Fence | 20 |
| Brown Wood Wall | 11 |
| Hedge | 8 |
| Fruit Tree | 20 |
| Flowers (incl. Planter) | 8 |
| Pillar | 35 |
| Fuel Pump | 18 |
| Light Post | 20 |
| Garbage Can | 15 |
| Red Post Box | 14 |
| Hydrant | 30 |
| Phone Booth | 25 |
Polar structures
| Terrain Object | Damage Rating |
| All Surfaces | 25 |
Desert structures
| Terrain Object | Damage Rating |
| Cacti | 15-20 |
| Tree | 16 |
| Damaged Tree | 24 |
| Hills (dunes) | 30 |
Jungle structures
| Terrain Object | Damage Rating |
| Small Trees | 12-20 |
| Small Ferns/Fronds | 5-12 |
| Large Ferns/Fronds | 16-20 |
| Large Tree (trunk) | 25-26 |
| Large Tree (fronds) | 8 |
| Large Tree (branches) | 20 |
Mountain structures
| Terrain Object | Damage Rating |
| Rocks | 20-30 |
| Hills | 30-50 |
| Trunks/Logs | 20 |
Cydonia structures
| Terrain Object | Damage Rating |
| Rocks | 40-80 |
| Small Crater | 40 |
| Large Crater | 70 |
| Pyramid | 70-80 |
| Pyramid Windows | 60 |
| Brain | 40 |
Weapon damage ranges
Projectile/energy weapons
These are the damage ranges of these weapons vs. terrain objects (0.25 to 0.75 their normal rated damage). Their damage range vs. living creatures is between zero and twice rated damage.
| Pistol | 6.5 - 19.5 |
| Rifle | 7.5 - 22.5 |
| Autocannon-AP | 10.5 - 31.5 |
| Laser Pistol | 11.5 - 34.5 |
| Plasma Pistol | 13 - 39 |
| Heavy Cannon-AP | 14 - 42 |
| Laser Rifle | 15 - 45 |
| Plasma Rifle | 20 - 60 |
| Heavy Laser | 21.25 - 63.75 |
| HWP Laser or Plasma | 27.5 - 82.5 |
| Heavy Plasma | 28.75 - 86.25 |
Explosive weapons
Damage listed is for center of explosion, decreasing with distance. Damage range vs. living creatures is between one to three times these values.
| Autocannon-HE | 22 |
| Grenade | 25 |
| Heavy Cannon-HE | 26 |
| Proximity Grenade | 35 |
| Small Rocket | 37.5 |
| Alien Grenade | 45 |
| Large Rocket | 50 |
| High Explosive | 55 |
| HWP Fusion Bomb | 70 |
| Blaster Bomb | 100 |