Real markets.Real consequences when you break them.

Each city's Market holds four things: a gold balance, an inventory map of every resource it has, a set of resources flagged for sale, and a list of active buy orders. Cities update these every simulation tick.

• Buy orders. When a city needs more of something than it has, it posts a buy order with a maximum price per unit. Gold equal to the potential payment moves into an escrow account — the city can't accidentally double-spend it on something else. Any trader can fulfill the order; payment releases from escrow on delivery.
• Sell orders. When inventory of a resource passes the excess threshold (150 units in default config), the resource gets flagged for sale. Traders see the flag and may buy. Selling automatically removes the flag once stock drops back below threshold.
• Sales tax. A running 4% tax is skimmed off every transaction. It flows up to the local faction treasury — which is then taxed again at the faction's posted rate.

The full Market struct lives in the C++ World Engine (src/data/Market.h). Cities, factions, and traders all interact with the same object — there is no separate "player economy" running on different rules.

Trade routes are persistent connections between two markets tracked by a single trader (or convoy). A route stores its primary resource, total completed trips, last trade time, a rolling price history, and a profitability flag. Routes that stop being profitable are dropped automatically.

Traders score candidate routes by:

• Profit margin — highest weight. A trader will not start a route under the 120 gp minimum-profit threshold.
• Distance — shorter routes are faster cycles. The base travel cost (60 gp) plus distance scaling eats directly into profit.
• Reliability — a route with many completed trips beats a new one of equal apparent margin.
• Competition — too many traders on the same route arbitrage the margin away. New traders look for less-contested options.

Geography's Trade routes section maps the four physical-route networks (Imperial Highway, Merchant Navy, Shadow Paths, Sky Routes). Each is a different terrain choice with different speed, cost, and risk profiles.

Because every market reads its own inventory and demand, a crisis spreads as a wave of price changes rather than a scripted event:

1. A famine event hits a region. Local food supply drops. The WorldEventGenerator tags the region with resource scarcity at severity 0.9.
2. Local prices spike. Cities post buy orders at the 75 gp ceiling. Traders running nearby food routes recalculate margins and accelerate deliveries.
3. Adjacent regions feel it. Surplus food gets drawn out, raising prices there too. The wave propagates.
4. Narrative seeds spawn. The event generator produces quest hooks: "Lithmere Faces Food Shortage" — collect-resource quest type, themes of scarcity and survival. Players see these as available board work.
5. A faction politicises it. If relations are tense, neighbours may exploit the famine: embargo, raid the convoys, or post emergency aid to buy influence. The simulation handles this; no scripted handler required.

Most quest hooks in the game are spawned this way rather than hand-written. The economy is the procedural quest pipeline.

A player picking up the Merchant profession runs the same rules as the NPC traders, which means:

• You cannot dump a large stock at one city — the supply modifier crashes the local price as you sell.
• You cannot stockpile cheap goods forever — buy orders expire after 48 hours, and the city you intend to sell to may run a surplus before you arrive.
• You cannot chain trivial price differences indefinitely — the 4% sales tax, 60 gp travel cost, and 120 gp minimum profit threshold all combine to kill margins on small arbitrage.

The big wins are crisis routes (high regional scarcity = high tolerances on price), first-mover trade routes (rare resources newly discovered), and long-haul luxury runs (mithril, dragon scale, enchanted dust) where the absolute margin per convoy easily covers the travel cost.