A supply dock during the First GLA War.
UN Crates, containing supplies.
A supply dock during the Second GLA War.
Supplies were the main resource used by generals during the GLA Conflict and the following Second GLA War. They were boxes containing valuable material Generals needed to construct buildings, train infantry, build tanks, aircraft, research upgrades, etc. They were found in almost every battlefield, often in Supply docks, and generals needed Supply Centers / Supply Stashes in order to take, storage, and process the supplies. The Americans used Chinooks, the Europeans used transverse rotorcrafts, the Chinese and the APA employed Supply Trucks and the GLA forced the workers to collect supplies as well as construct buildings. Generals often built supply centers near supply docks to provide faster gathering. Supply boxes are not poisonous, but count as structures which take up space and can block vehicles from passing through them. Supplies could be found in Supply Docks in set quantities, or scattered around the area as small piles of boxes.
UN Crates also exist as another form of supplies. They do not require a specialized logistical unit, as the first unit or structure that contacts them will claim the crates' contents as supplies to their owner. They appear in various missions and maps, and are also generated by the American Supply Drop Zones which receive them by air from transport aircraft. Some UN Crates provide a bonus unit instead of supplies upon being claimed, however, these crates are pre-placed on custom maps and are not part of standard gameplay.
Supplies are limited in quantity, but each faction has a secondary income source. China can use Hackers to slowly generate them, the GLA can construct Black Markets, and the USA relies on the Supply Drop Zone. Chinese factions can steal supplies from Supply Centers and Stashes using the Cash Hack ability, as well as Black Lotus. Secondary sources of income, however, are immune to this form of theft. The GLA can also use its Cash Bounty ability to raise funds, deriving money from destroyed enemy units. Additionally, an Oil Derrick will provide $1000 on capture, and $200 every 12 seconds thereafter.
The GLA's salvage mechanic can also provide supplies if crates are collected by one of their units, provided that said unit cannot be upgraded by them.