The X series games are unique in their depth, simulating an entire universe of NPC ships and stations, forming a realistic economy. Each game consists of a huge universe, simulated from the bottom up. Hundreds of stations, and thousands of ships, trade goods among themselves. Prices change based on supply and demand; resources are mined and processed in several stages. This economy is linked directly to the simulation of major conflicts, in a universe with dynamically-acting factions. Every player decision can dramatically change the future of the game universe.