"Synth" is a term used in Half-Life 2 to describe a series of bio-mechanical constructs utilised by the Combine. These entities come in a number of configurations suited for different purposes such as reconnaissance, transport and combat. Synths have been officially described as "self-replicating robots that evolve"; they are created from a combination of mechanical components and organic features from various alien species that the Combine have conquered.
Overview[]
Synths always appear as average to large insect-like or arthropod-like creatures, usually with segmented legs or antennae-like sensory structures, recalling locusts, crabs or similar beings.
It is unknown how many of the Synths presented in the series are 'true' to their initial species or forcefully evolved by the Combine, since the Combine modify their appearance by adding mechanical equipment and weaponry. It is also unclear whether they originally were fully organic or were already cyborg creatures when the Combine enslaved them, and if they all come from the same planet (mirroring the Xen creatures that were also brought from other worlds and, for some of them, also enslaved). The Strider however appears to have a brain, as seen in Episode Two (this is the only known Synth to possess any "organ" at all). It is also suggested that some were created from scratch by the Combine (the City Scanner for instance bears some design similarities with Synths, while being fully mechanical).
Synths do not necessarily arrive on Earth after having been modified, as the City 17 Citadel features factories where Synths are modified. For instance, Stalkers can be seen working on Gunships in the lower levels. Synths are also never observed to be "self-replicating" in-game, but seem to be raised and/or manufactured by the Combine.
Their carapace-like flesh is largely immune to small arms fire (with the notable exceptions of the Hunter and Shield Scanner) and bullets striking it produce a metallic 'ping' noise. These outer shells can be ripped open with enough force, however, as demonstrated when DOG tears a Strider's head open in Episode Two. The only weapons that are known to be effective against the larger Synths are explosives (such as the RPG, the MP7's secondary fire, or the Magnusson Device) and the Combine Energy Ball.
It is likely that Synths were the primary forces used by the Combine during the Seven Hour War as the human-derived Combine units, such as Overwatch Soldiers, Hunter-Choppers, and APCs, would have only started appearing after the Combine rule on Earth had been established.
Known Synths[]
- Combine Dropship
- Combine Gunship
- Hunter
- Shield Scanner
- Strider
- Mortar Synth
- Crab Synth