Some game systems have a Streetwise skill. Here are things that it's usually related to:
- Knowing about urchins, pick-pockets and urban gangs, their organization, codes, behaviors
- Knowing who's where in the urban food-chain, who's pulling the strings, who's dangerous, who's a lackey of whom
- Gathering underground rumors
- Circulating your own rumors
- Knowing various usually inconsequential people that can provide specialized help (from a cobbler to a locksmith)
- Knowing the best places in town for various things (where's the gambling, where's the illegal dealing, ...)
- Knowing how to move through a city, either to escape pursuers or catch runaways
- Being able to blend in with the crowd and pass off as a local, or at least avoid attention
- Haggling with merchants, especially black market ones?
Which Pathfinder skill or skills would best represent these? Should Traits also be involved?
At a glance, it seems Knowledge Local could do a lot of this. Diplomacy and Bluff already fit some of the actions, though not specifically for urban environments I think. Some of it would fit "Survival (Urban)" if it was a skill, which the Urban Ranger does some of.