Gameplay

Gameplay in *Dark Colony* plays out in real time, and focuses on two things: Preparation for conflict - and combat.

## Resourcing

The main source of energy is the precious gas called Petra-7. With the
use of the resource extraction units such as the Human Exploiter, or the Gray Brozaar,
this gas can be collected from erupting vents and converted into Petra Units.
Some Petra-7 vents are stable and provide
long lasting supplies of the gas. Other vents,
however, may either lay dormant or erupt
during game play.

All city structures are built on a stable Petra-7 vent. Energy flows at a constant rate
when a city is present. In the bottom right of the screen is the Petra-7 Unit energy
meter, or "money" you have available to build structures, units, and upgrades. The
number on the counter automatically decreases when a unit or structure is bought or
upgraded. The number increases when a resource gathering unit is deployed on a
Petra-7 vent, or finds an underground Petra-7 deposit.

### Gathering resources

In order to gain energy, you must collect Petra-7. To collect Petra-7 you need a
resource gathering unit. Most missions that allow for resource gathering start you with
one of these gathering units. If necessary more can be built at the main city structure.
If you want the energy to come into the city faster, more resource gathering units can
be built to mine from other Petra-7 vents.
Resource gathering units must be directed to and
deployed on Petra-7 vents manually. Once
deployed, they should be defended by units with
combat capabilities because the gathering units have
no defensive capabilities themselves. If threatened,
these units can be un-deployed and moved.

When a resource gathering unit is built it does not automatically search for a vent. It is
recommended that you scout out a vent with another unit before actually sending the
gathering unit itself. This way is much more inexpensive if the exploring unit is lost.
Also, the gathering unit usually has a very small vision radius in comparison to the
other units in the game. Once a suitable vent is located, select the gathering unit by
left-clicking on it. Then put the mouse cursor over the vent and left-click again. Once
the unit has reached the vent it automatically deploys itself, unless the vent has
already been taken. In this case, the unit occupying the vent must be destroyed
to remove it.

## Unit stats

When a unit is selected an inverted triangle appears over it. This is the
unit1 s health indicator. The color of the triangle depends on the amount
of hit points the unit has left. The color indicates the unit's health:
green is healthy, yellow is damaged, and red is severely damaged.
Some units have power in addition to their Health. These units have
a circular bar of colors which show the level of power they have. A
full circle of power goes from red to green, red being the lowest
power, and green being the highest.

### Fog of War

All terrain at the start of a campaign mission is not revealed,
and thus black, until a unit of your team has explored the area.
Once a unit moves towards the undiscovered terrain the
darkness recedes, leaving the terrain visible both in the main
game screen and the mini-map in the upper-right of the
screen. After the unit has left the area, a fog of war covers the
position behind it, darkening the main game screen slightly
and showing only terrain, vents, and buildings, not enemy units. Certain units have a
larger "vision radius" than others, and are better at exploring unexplored terrain.

### Line of sight

Many objects in the game actually block your unit's vision, or
in some cases shrink it. Large plants, rocks, and other terrain
obstacles provide good cover for ambushes and other tactics.

### Night and day

Like Earth, Mars has its own day/night cycle which is roughly
8 minutes real time for each phase. During the daylight hours
the humans have the larger visual range, but at night, the
grays have the superior vision.

## Colony bases

Critical to most missions where you have a base in the game is the defense and
maintenance of all city structures. The city structures are necessary for collection of
resources, the building of units, and artifact extraction and research.
Colony Foundations

Each colony, both human and alien, is built upon a five-sided
plate. Each plate is positioned over of an existing Petra-7 vent
which is mined continually, allowing a little money to trickle in.
To be able to develop any of the units required to fight the
war, the player needs to build a series of structures to enable
research and construction.

## Combat

Combat is real time and requires a separate article to describe properly.