A Dynamic is a relationship between two neighborhoods in a city. Dynamics are either stable - unlikely to change - or unstable - constantly in flux, always in danger of collapsing or mutating.
Two neighborhoods are connected via artistic expression. One may house artists who draw inspiration or receive funding from the other. Artists of different traditions may cross-train, creating a new and unique tradition.
Two neighborhoods are connected via artistic expression. One's artists may be exploited by patrons from the other, or the artists are improperly borrowing from a neighboring culture. Two neighborhoods may have competing cultural and artistic traditions.
Two neighborhoods are connected via criminal activity, from petty theft and pickpocketing to smuggling to murder. Organized crime cartels, thieves' guilds, etc. from one neighborhood may prey on the other. Or legitimate business in one is being propped up by criminal activity in the other.
Two neighborhoods are connected via criminal activity, From petty theft and pickpocketing to smuggling to murder. Gang wars between rival factions, a single criminal mastermind, or open corruption are all possibilities.
People from one neighborhood buy or sell goods and services to the other. Advertising, word of mouth, or tradition might entice new visitors. Supply and demand are roughly balanced, or the market is adaptable enough to cope when they aren't.
People from one neighborhood in the dynamic buy or sell goods and services to the other. Market prices are volatile, or there may be an imbalance in supply vs. demand.
Two neighborhoods interact through arcane goods and services. One may supply the other's needs, or contain a natural source for something vital or valuable. Or both may contribute ingredients to complete a final thing.
Two neighborhoods interact through arcane goods and services. Although one needs what the other has, the exchange is threatened by mistrust, scarcity, or the volatility of the materials and processes themselves.
Two neighborhoods are connected by something happening outside the city. This could be immigration, trade, religious or political action, cultural trends, or something else.
Two neighborhoods are connected by something happening outside the city. Whether people, things, or trends, life in the neighborhoods is being shaken up by it.
Two neighborhoods are connected by the production of goods. One may supply workers and/or raw materials for the other, one may buy what the other makes, or the two may cooperate in other ways.
Two neighborhoods are connected by the production of goods. Labor disputes, material shortages, sabotage, or technological progress can all make that process unstable.
Two neighborhoods interact via power, influence, and leadership. There is a long-standing arrangement or entrenched leadership keeping things stable. Enough people, or the right people, like things as they are and work to keep it that way.
Two neighborhoods interact via influence, and leadership. One might dominate another, depend on another for legitimacy, or prioritize or ignore the other. When the corrupt edifice falls, who will be beneath it when it finally falls?
Two neighborhoods play off each other via fashion or pop culture. The trends of the moment may shift between the two, or the tension between them may be what creates the magic. The results are disseminated through parties, performances, and gossip.
Two neighborhoods play off each other via fashion or pop culture. One may be trying to crush the other's creative efforts, or upstage the other in increasingly desperate ways. The results may be soulless, gaudy, or seen as needlessly aggressive.