Item weights are represented in Strength units. For example, an item of 18 weight units requires a bare minimum of 18 strength points for you to carry without suffering an encumbrance penalty on your TU refresh rate.
Therefore, if you want to micromanage your items for a very weak soldier, add up the weight of all the items you want to issue the soldier, then compare the result against the soldier's strength. Add or remove items as necessary while keeping the weight vs. strength level balanced.
Tip: All small items (one inventory square) are 3 weight units.
Item Weights do not directly correlate to weight (e.g. in kilograms), and the relationship is not even a linear one. Think of it instead as a measure of how much the item causes Encumbrance. The Weight value should not be considered an actual physical quality such as mass.
Due to a helpful bug, clips or shells automatically loaded into carried weapons by the game engine for the pre-battle Equipment Setup screen are not counted for weight. This changes as soon as you unload or reload the weapon (even during the Equipment Setup screen); the full weight is counted thereafter.
In the battlescape display, an item lying on the ground might represent a pile of items. In this case, it is the heaviest item displayed (usually a corpse).
The following represents a complete list of item weights for X-Com UFO Defense/Enemy Unknown.
|Ballistic Weapons||Energy Weapons||Explosive Weapons||Corpses||Miscellaneous|
* Technically these corpses are the same object type, and have only 1 entry in OBDATA.DAT
Quick reference for common item sets
Note that for all weapons that are loaded by the game during setup, subtract the ammo weight from the "Loaded" values given below. The ammo weight only applies if you load the weapon yourself. Think of this as "Free-loading". :)
|Loaded Rifle + 3 one-space items*||20|
|Laser Rifle + 3 one-space items||17|
|Loaded Heavy Cannon||24|
|w/ extra clip||30|
|Loaded Auto Cannon||24|
|w/ extra clip||29|
|Loaded Rocket Launcher + 3 Large Rockets||42|
|w/ all Small Rockets||34|
|Loaded Heavy Plasma + 3 one-space items||20|
|Loaded Blaster Launcher||19|
|+ 5 Blaster Bombs||34|
|Loaded Small Launcher + 2 one-space items||19|
|Loaded Plasma Pistol||6|
* All one space items (grenades, ammo clips, motion scanner, stun bombs) have a weight of 3 in UFO Defence (but not always in TFTD).
The remaining items cannot be picked up, but are included for completeness sake:
Corpses (continued): Reaper.................50 Cyberdisc..............50 Sectopod...............50 Hovertank..............50 Tank...................50 Male Civilian..........30 Female Civilian........50
Note that for the large units, each quarter is worth 50 units.
Unused Items: Unused slot.............1 Unused slot............22 (Same as above, but heavier) Unused slot............22 (Ditto) Unused slot.............1 (Appears to be a type of plasma clip) Unused slot.............4 (Pistol variant. Slower, less accurate, 1x1 in size) Unused slot.............4 (Unknown) Note: In TFTD, the above slots are used by the gauss clips and the drills
The game has six unused item slots. Unfortunately, there's no known way to get them into any of the item transfer screens. Otherwise, they'd make six extra weapons, clips, or grenades. They can be added to the Skyranger with a ship store editor, and they'll appear in combat, but their OBDATA.DAT entries have to be tweaked so that they work.
The first three unused slots are an unnamed multi-barrelled laser. Prime attracting feature: 15% TU Autofire @ 50% accuracy with 40 laser damage. It's assumed to be a multi-barrelled laser as the default battlescape image shows the autocannon, although uses the laser rifle for its inventory image.
Sorted by item weight
Here's an alternate listing sorted by Item Weight. Does not include items that can't be picked up:
|3||Heavy Plasma Clip|
|3||Plasma Pistol Clip|
|3||Plasma Rifle Clip|
|22||Soldier in Jumpsuit|
|24||Soldier in Personal Armor|
|26||Soldier in Power or Flying Armor|