In space empires II-V, all planets (and asteroids) have 3 percentages in their information tab, one for Minerals, Organics, and Radioactives. In the stock game, values ranged from 0-150% for planets and 50-300% for asteroids. These values are multiplied into the resource production of a planet, (and they Do stack with other multipliers). For example, a planet with a value of 50% for minerals and no other modifiers would only produce half the normal amount of minerals. For this reason, values often play a large part in what type of planet it is. A planet with a high mineral value but low organic and radioactive value would most likely be a mining colony, while a planet that is very large but has low values for everything might make a good shipyard or research compound. In a Finite Resources game, the percentage is replace by a number that decreases at 100% rate when mined, and produces nothing when it reaches 0.