In Space Rangers, a relatively peaceful interstellar coalition is invaded by a powerful enemy; the organic warships of the Klissans. The player is a Ranger, one of a group of non-military volunteers who are given small ships, free rein and the task of helping to battle, understand and ultimately defeat the menace.
The game is dynamic and open-ended in a fashion that has been compared to Elite and Star Control 2. Trade prices on planets follow supply and demand, the wars are ongoing non-scripted conflicts, computer-controlled ships have individual capabilities, goals and relations, etc. There are even several ways to complete the storyline. The games have turn-based space travel and combat, optional shoot 'em up sequences and occasional bits of text adventure.
Long ago now wise and peaceful Gaal race was very aggressive and was creating a huge number of colonies. Due to large space distances it created hyperjumper which could make holes in the galaxy. Soon one of the colonies met with Klissan fleet. Although Gaal colony ships tried to communicate with Klissan ships they failed to do that and were destroyed. Soon Makhpella, the mothership of all Klissans and Klissan fleet invaded all outer Gaal colonies. Gaal colony fleet was completely helpless and in order to save original Gaal territories and Gaal motherland itself from invasion they decided not to jump back and make Makhpella trace the route there but to blow up the remaining other colonies using the hyperjumper.
Not very long ago everything was started by Peleng captain called Rachekhan who was one of commanders of Peleng fleet. He was thrown out of the fleet and became a pirate. Since he had an access to secret documents and weaponry he stole a hyperjumper. While travelling with it he met Makhpella. It considered Rachekhan's pirate fleet as an enemy and started chasing it. During the chase Rachekhan and Klissan fleets went through interstellar coalition sectors so Makhpella spotted IC sectors and now knew its location and identified all IC races as foes. So the war started.
Source: Wikipedia, "Space Rangers (video game)", available under the CC-BY-SA License.