City 17
Introduction
City 17 is the main human population center on Earth under Combine control, and is probably located somewhere in Eastern Europe. The city also houses the Citadel (although it is not the ONLY Citadel on Earth), which serves as an administration center for all Combine operations as well as Dr. Breen's headquarters.
Architecture
City 17 represents an interesting juxtaposition between the old world and the alien Combine influence. Keep in mind that the very nature of the Combine is to assimilate other species into their power; they adapt rather than destroy and rebuild. Apartment buildings are converted into command centers; sentry towers are attached to tall office buildings; Nova Prospekt is used as a human experimentation lab. The building's original function should be clear to the player, as well as the Combine's perversion of that function.
The buzzword for City 17 when Half-Life 2 was in development was "Eastern European architecture". This basically means that buildings should seem old and strong; brick, stone, and to a lesser extent concrete work best. Balconies, pillars, and spires are common. Certain buildings can appear elaborate if they are for public use- museums, libraries, government buildings, and so on. Check out pictures of buildings in western Russia, Poland, the Czech Republic, and nearby nations for ideas.
Environment
City 17 is, obviously, a city, and as such buildings should work as borders for a level. Otherwise, Combine fences or, for smaller gaps, police themselves can be used. Buildings should be large and tall, not only to create better visual blocking but to create a slight claustrophobic feel, which may be desired.
Again, since this is a city, there is considerably less vegitation than other areas. Grassy areas should appear to be gardens or lawns, not open fields.
NPCs
Virtually any NPC will fit in City 17, with perhaps the exception of antlions, as City 17 is probably fortified against wildlife and is located away from the coast.
Since almost anything can go in the city, wise NPC placement becomes a matter of timing. If making a single-player map, consider when in your storyline this level occurs. If making a multiplayer map that includes NPCs, focus on the player's abilities at the time they would encounter the opponent or ally.
Reference
Because of the importance of City 17 and the amount of time spent, only major or unique portions of the city are referenced below.
