Future Earth X Gate

In the near future America has fallen into a civil war which led to World war 3. The war has come to an end and a new nation was born the New Coalition of Republics or NCR for short. Your family has a strong relationship with the NCR, as your family now runs their military and other key assets to this new nation. The new metropolitan city known as "Tyler City" was attacked by a unknown army and and a unknown gate has appeared in the center city. What is in store for you? As a soldier you must serve you country.... or your family in that case.
I will put my own twist on the GATE storyline. It will follow some of the Gate storyline but will be its own story later on.