Combine

 The Combine' was the main opposing force in the game Half'-life 2 ''created by Valve. The Combine were made up of multiple different universes set across different dimensions, made up of countless amounts of different species, thus the reason why it's named "Combine," meaning the combination of all species. The Combine were known for conducting inhumane experiments on many different creatures, and had various devilish torture methods.

Through the game of Half-life 2, you come across a variety of Combine bioengineered creatures (Named Synths) and their Combine Soldiers (C refers to them as the "Transhuman Forces of the Combine"). The Combine Soldiers had a variety of armor that mainly served no other purpose then to display their rank in the Transhuman army. Other variants of Combine soldiers were "Civil Protection" or "Metro Police" which were the main police force of City Seventeen. These humans had willingly chosen to work for the combine, even though they were responsible for enslaving the planet. The Synths varied as well. A brief list of the Synths known in Half-life 2 are:


 * 1) Striders


 * 1) Hunters (From Half-life 2: Episode 2),


 * 1) Combine Dropships


 * 1) Combine Gunships


 * 1) Shield Scanners


 * 1) Mortar Synths


 * 1) Crab Synths

All Synths previously listed are encountered in game. The Combine on Earth was originally lead by Dr. Breen, but superior to Dr. Breen are the "Advisors" these seem to be the highest up in the combine world, however not much is known of them at this time.

The combine took over the planet earth around the 1980's, at the time of the renaissance cascade. the Xen forces attacked the Black mesa reaseach facility, and alerted the combine of earths presence. in just 7 hours the combine had complete controll over earths military forces.

Dr. Breen surrendered the planet, and the Combine rewarded him as the administrator of earth.

20 years later the combine had rounded up all of humanity into massive cities (with numbers, not names e.g; city 17, city 14...) and activated a suppresion field that prevented all humans from giving birth. the combine were slowly choking the planet dry.

It appears many of Earth's species were extinct too, with just birds and leeches being encountered in the game. The reason for this is that Xen species unfamiliar to Earth creatures attacked and killed them.

The oceans seem to have lowered aswell.