This is going to be pretty short. I decided, just for the fun of it, to try playing a game on the Gigantic map. There were six alien races on the tough difficultly level, and the settings were set to the defaults.
I was playing the Thalians, and I had the good fortune to be in a reasonably isolated part of the galaxy. After researching Barren and Toxic colonization, I had a large number of planets to work with. As is my custom, I spent very little money on my military initially, with the plan being to at some point during start building up my forces very quickly under a good economy with good technology.
When the only race I knew, one of the minor races, declared war on me, I decided that the time was now. I built medium-sized ships loaded with missiles, and I built a half-dozen fast transport ships. Their resistance was quickly ground under the heels of my troops.
So, I kept building my missile cruisers, hoping to build up a large enough force that the other races would quit demanding money from me. I had just crossed the line from weakest military to second-weakest military when I got word that the Dread Lords had invaded the galaxy. Worse, they were in my back yard!
Fortunately, I noticed that they hadn't built any of their ships yet. I mobilized the remaining transport ships and moved them in the direction of the Dread Lord homeworld.
Two turns away from the Dread Lord homeworld, another special event popped up: Pirates had invaded the entire galaxy. I checked out one of these pirate fleets: they had devastating numbers of laser weapons.
My invasion fleet managed to evade the pirates and take over the Dread Lords (earning me the fastest warp engine in the game), but the pirates quickly demolished _every_ ship and station in my fleet. I could not build more ships, because as soon as I did, a pirate fleet was there to eliminate it.
At first I thought, "I'm screwed." And then I realized I could use this to my advantage. I went to the domestic spending screen and turned my research knob as high as it would go, and put the remaining production into social construction. Then, I made my way through Invention Matrices and Discovery Spheres, putting every effort into achieving technological victory, using the pirates to defend my territory from my stronger opponents. Eventually every other race declared war on my, but I was virtually untouchable.
Until some crazy scientist found a wormhole that released robot peacekeepers into the galaxy. They made quick work of the pirates, and continued to protect me from the occasional Torian invader. I lost two planets before it was over, but in the end I emerged victorious, thanks in no small part to the pirates who massacred my entire fleet.