Minerals are the main resource in StarCraft. They are mined from mineral fields that are clustered together in various locations on a map. These locations are where players build their bases. Minerals are gathered by workers that mine 5 minerals per trip and return them to the Townhall building.
A normal base has eight mineral fields, consisting of four large nodes with 1800 minerals per field and four small nodes with 900 minerals per field, for a total of 10,800 minerals per base. The remaining number of minerals in a particular mineral field can be seen by clicking on it.
Once a mineral field has no more minerals left it is depleted and disappears from the map. In order to be able to gather minerals throughout a game, players then have to secure additional bases.
Sometimes maps utilize mineral fields which only contain 5 or 10 minerals to make terrain obstructions. These fields can then be quickly removed by having a worker mine them for one or two trips.
Rich Mineral Fields
Some maps contain bases with yellow-colored Rich Mineral Fields, which allow workers to carry 7 minerals per trip instead of 5. A base with Rich Mineral Fields is referred to as a "gold" base.
A gold base usually has only 6 mineral fields instead of 8: three large nodes with 1800 minerals per field and three small nodes with 900 minerals per field, for a total of 8,100 minerals per base.
Because workers carry more minerals per trip when gathering minerals from Rich Mineral Fields, gold bases mine out faster than normal bases.
The Terran MULE is a special unit with timed life that mines 25 minerals per trip on any type of mineral field.
Vespene Gas can be harvested from a Vespene Geyser once a particular building has been built on top of it. These are the Terran Refinery, the Zerg Extractor, and the Protoss Assimilator. Workers gather 4 gas per trip and return them to the Townhall building.
A normal Vespene Geyser contains 2,250 vespene gas. A normal base has two Vespene Geysers.
A normal base thus contains a total of 10,800 minerals and 4,500 vespene gas in a 12:5 ratio (2.4 minerals per gas, or 0.416 gas per mineral).
A Vespene Geyser is depleted once it has no more gas, but the geyser as well as the building on top of it remain on the map. This is indicated by the geyser no longer emitting green gas or the gas building glowing red.
Rich Vespene Geysers
Some maps contain bases with Rich Vespene Geysers. These only differ from normal Vespene Geysers in that workers gather 8 gas per trip instead of the normal 4.
A Rich Vespene Geyser usually contains the same amount of vespene gas as a normal geyser, but since bases with Rich Vespene Geysers usually only have a single geyser, their total amount of gas is only half that of a normal base. Because of the double amount of gas per trip for workers harvesting Rich Vespene Geysers, these geysers are also depleted twice as fast as normal geysers.
Below are some calculations on how fast and efficiently workers gather minerals and vespene gas in various scenarios.
A worker occupies a mineral field for 1.99 seconds. It then pauses for approximately 0.3571 seconds before returning at full speed. The next worker can already begin operations during the pause. This applies equally to normal minerals and gold minerals. In theory, a fully saturated mineral line with 8 mineral fields can therefore mine no more than 1206.03 minerals per minute (60sec / 1.99sec * 5 minerals * 8 mineral fields). The corresponding number for a fully saturated Rich mineral line with 6 mineral fields is 1266.33 minerals per minute (60sec / 1.99sec * 7 minerals * 6 mineral fields). However, due to workers commuting between mineral fields in search for one that is not occupied, these ideal numbers are never reached.
With two workers per mineral patch, a large mineral field with 1800 minerals will exhaust after 15 minutes, whilst a small field with 900 minerals will exhaust in 7.5 minutes. The corresponding numbers for Rich mineral fields are approx. 11 minutes and 5.5 minutes, respectively. Note that these numbers do not take into consideration Terran MULEs.
MULEs can mine while other SCVs are mining, but only a single MULE can mine a mineral field at one time. Their time occupying a field is longer than a worker. The effective mining rate of MULEs is approximately 3.45 times that of a SCV's on near patches and approximately 3.94 times that of a SCV's on far patches. MULEs mine 225 minerals on both near and far mineral fields, although when mining near mineral fields they drop 25 minerals since their timed life will run out while returning cargo. With MULEs, Terran can mine patches faster than any other race and can maintain similar levels of mineral income with less secured patches for mining, thereby compensating for their worse production capabilities.
- One worker on one mineral field gathers 55-60 minerals per minute (80-85 for gold minerals), depending on distance.
- Two workers on one mineral field gather 110-120 minerals per minute (160-170 for gold minerals), depending on distance.
- Three workers on one mineral field gather 143 minerals per game minute (200 for gold minerals), regardless of distance.
Having two workers per mineral field is generally considered optimal. When more than two workers are available per mineral field, it is usually better to add additional base(s).
This means that:
- With two workers per mineral field, a base with 8 mineral fields will harvest about 925 minerals per minute.
- With three workers per mineral field, a base with 8 mineral fields will harvest about 1140 minerals per minute.
These numbers are only slightly higher for gold bases because they only have 6 mineral fields.
Workers gathering gas have to spend 1.415 seconds in a Vespene Geyser before returning at full speed. A fully saturated geyser can therefore procure no more than 169.61 gas per minute (60sec / 1.415sec * 4 gas).
A normal Vespene Geyser with 2,250 gas will exhaust after 13.25 minutes of saturated extraction.
- One worker on a geyser gathers 61 gas per minute.
- Two workers on a geyser gather 123 gas per minute.
- Three workers on a geyser gather 163 gas per minute.
Although the amount of gas per minute per worker is higher when having one or two workers on a geyser, it is still considered optimal to have three workers on a geyser.
- With three workers per geyser, a standard base with 2 Vespene Geysers will harvest about 325 gas per minute. The number is the same for a base with a single Rich Vespene Geyser.
The production of almost every unit requires an additional resource: Supply. The amount of supply can be increased by the building of certain buildings or units.
- For Terran, Supply is increased by building Supply Depots (+8), Command Centers (+15) and Calldown: Extra Supplies (+8).
- For Protoss, Supply is increased by building Pylons (+8) and Nexuses (+15).
- For Zerg, Supply is increased by producing Overlords (+8) and building Hatcheries (+6).
Building either of these will increase the amount of supply a player is able to spend. The maximum amount of supply for any player is 200. Due to the inefficiency of building Command Centers, Hatcheries or Nexuses for supply, these should never be built for this purpose only.
The term "Supply Block" or "being supply blocked" means that the player does not have any supply available to build additional units.
Note: Supply is sometimes called Psi for the Protoss and Control for the Zerg. Another general term for supply is Food.