There are five resources available in OGame: metal, crystal, deuterium, energy and dark matter. Metal is the most abundant resource and can be obtained natively from metal mines. Metal is used in large amounts for construction of planetary structures, fleets, defenses, and technological research. Crystal is the second most abundant resource and can be obtained natively from crystal mines. Crystal is used in smaller quantities for the construction of planetary structures, fleets, and defenses, but is used in large amounts in technological research. Deuterium is the rarest resource and can be obtained natively from deuterium synthesizers. Deuterium is mainly used as fuel for a player's fleet to perform a mission, and for technological research. It is also used in small amounts for accessing the galaxy screen to obtain an overview of the OGame universe and in scanning enemy fleet movements. Energy is required for all mines to operate. The efficiency of a mine depends on the amount of energy surplus on a planet. Energy can be obtained through solar plants, fusion reactors, and solar satellites. Energy is also required for the construction of Terraformers and for researching the graviton technology. Metal, Crystal and Deuterium can be obtained through: * Mining: Metal mines, crystal mines and deuterium synthesizers obtain metal, crystal and deuterium respectively from one's own planet. The larger the mine, the faster the rate of obtaining resources. Planetary resources never run out and can be continuously mined. * Raiding other planets: A player can decide to send an attacking fleet to an enemy's planet. If the player's fleet destroys all of the enemy's fleet and defensive structures, up to 50% (depending on the cargo capacity of the attacking ships) of the enemy's stored resources can be retrieved. * Harvesting debris fields: destroyed fleets form a debris field around the planet it was destroyed. Debris fields consist of metal and crystal. * Fleet Crashing: Stronger players can "fleet crash" weaker opponents, which is the act of destroying another player's fleet for the purpose of collecting the debris that remain after the battle and recycling the resulting debris (only metal and crystal can be obtained this way) and 30% of all ship's metal and crystal can be obtained in such a manner. * Trading: Players can negotiate a trade sequence where they swap different resources at an official rate. * Expeditions: Players can send their fleets out and get random things in return. These are risky as there is a chance of losing your fleet. Players are ranked according to their points, one point is awarded for every one thousand resource units spent, likewise one point is taken away for every one thousand resource units lost. Points can be gained from constructing buildings, ships, defenses, and from researching new technology, but points can be lost when a player's ships and defenses are destroyed by another player or when a colony is surrendered. Dark matter is obtained mainly by buying it with real money. It can also be obtained in smaller amounts through expeditions, which are very risky due to the possible loss of fleets. Dark matter allows access for a player to become a commander and hire officers. All purchased effects last 3 months for 100,000 units of Dark Matter and 1 week for 10,000 units of Dark Matter.