The military power of any empire, galactic or planet-bound, large or small, is always in direct proportion to its economic power. Empires with efficient factories, well-established trade routes, and high technology, will (in the end) triumph over less organized states. In a galactic empire, the economic power of an empire is measured by the production of its worlds. Every year worlds take in the necessary raw materials and build up the military muscle needed to exert imperial influence over a hostile galaxy. Every year the emperor or empress uses the imperial starfleet to defend worlds against adversaries and expand the realm's dominion over still more worlds. Year after year the cycle repeats, economic and military power hand-in-hand, each nothing without the other. The importance of military power is obvious to the most naive; the importance of economic power is understood only by the inspired and experience.
Merely having more worlds than any other empire will not automatically bring more power. The kinds of worlds in the empire are very important:
Of course, these guidelines should not be rigidly adhered to, only taken as advice. The consolidation of power is the goal of any imperial ruler. Worlds, in all their myriad variations, are key to that power.
Every world produces resources for the empire, some worlds build starships, others mine metals. The principal resource produced by a world is determined by the type of the world, but any world will still produce enough raw materials and supplies to survive. For example, a world that has been designated as a jumpship base will mine enough metals and trillum to support its ship-building industry. The industry of a world is balanced so that all the needed resources are produced.
Designating the type of a world is not the only way that a ruler may use to control production. An emperor or empress may also force a world to produce less raw materials than it needs, thus increasing the production of the principal industry. For example, a jumpship world normally produces (approximately) 100% of the metals that it needs to build jumpships. A ruler may decide to decrease that to 50%. In that case, more of the world's industry will be devoted to building jumpships (and more jumpships will be built). The downside, of course, is that the emperor or empress must insure that the world gets 50% of its metals from another world.
Because of economies of scale, a world that concentrating on building jumpships (while importing metals from another world) will produce more jumpships than two worlds producing both jumpships and the metals that they each need. In general terms, concentrating industry on the same world will increase production geometrically: twice as much industry will produce four-times as many ships.
Ambrosia is one of the rarest substances known in the universe and although its structure is well-understood, its molecular configuration is so complicated that even the most advanced civilizations cannot synthesize it. Only a few special worlds have the proper climate and biosphere needed to manufacture this drug.
Worlds can be addicted to ambrosia by simply providing the population with a few hundred kilotons of the drug. After a few years, most people will be addicted and the industrial capacity of the world will increase. Thereafter, you must provide the world with roughly 11 kilotons per billion people per year to sustain their addiction. The only way to cure the addiction is to withdraw the supply of the drug. This method, however, always leads to colossal drug-induced riots.