A Road Taken
The year 2010: Tomorrow A group of scientists cooperating worldwide across the internet and employing various published results from the Large Hadron Collider make an amazing discovery: an anti-gravity engine which should theoretically be able to surpass the limits on velocity set by Einstein's theory of relativity.
Amazingly, this device is also cheap: about the cost of a jet engine. News of the results and access to them soon spread worldwide (all the group's findings were posted online). It is quickly found that attempts to use the drive to time travel simply fail catastrophically, (though not catastrophically enough to be useful as a weapon).
The group's results quickly spread and are replicated in various other labs around the world. Much of their material is posted on the internet, and rapidly disseminates, with even third world states gaining quick access to this new method of travel.
A second, unusual effect of the drive was that it was able to 'jam' fission reactions over a certain scale. The controlled burn of a reactor operated fine, but the uncontrolled fury of a bomb, or even a fission triggered fusion device could simply be made to fail over a wide area (up to several hundred miles in radius). A final application was the sending of instant signals between two previously established drive locations.
Or story begins one year later: On April 6th 2011, when the first space craft fitted with the new drive begin their race to the stars.
Rules and stuff
Road Taken is a nation SD, each PC plays one nation extent in the world today. Larger nations like US and China are subject to more restrictions and potentially bad luck than smaller ones in order to balance out their large initial amount of power.
All nations have the ability to build Anti-gravity engines which allow easy, large scale lift out of the atmosphere, but otherwise have current levels of technology. Ships still require chemical drives as their anti-gravity systems do not do anything to actually power them, they simply reduce the amount that needs to be pushed around.
FTL travel is done at a rate of about 1 light years per week.
Ships have a maximum initial mass of 1000 tons, this is the maximum that the anti-gravity unit can be made to effect at the start. The smallest anti-gravity units can be made to fit into a vehicle the size of a fighter jet.