Simulation layers
In essence, the environment for The Great Game is broadly descended from games like the original Elite space trading game, and Sid Meier’s Pirates!, with some elements from political simulations like for example SimCity.
That is to say there is
An economy simulation
As goods are transported between cities, prices rise and fall based on simulated production and consumption. As prices of commodities rise, more citizens will take up trades which produce those commodities. The simulation needs to be sophisticated enough that, for example, as a city grows richer, its citizens may switch from preferring low cost textiles, eg perhaps wool or linen, to higher cost textiles, such as for example silk (or more complex weaves, or…) Similarly for foodstuffs and for beverages.
Agricultural production will be affected by climate simulation.
This is mainly a land game. Broadly, caravans take the place of ships in Elite or Pirates! Caravans are broadly made up of camels, although some may use mules or possibly horses. In any case, a merchant may own camels and hire camel drivers, or may hire contractor drivers who have their own camels; and there will also be whole teams of camel drivers with their animals which can be hired in a single contract.
A political simulation
Broadly, aristons claim territories in an essentially feudal arrangement, drive out outlaws, and levy taxes.
An ariston will be popular if their regime is stable, if taxes are low, justice is considered fair, oppression is low and depredations by outlaws are minimal. The more unpopular an ariston is, the more resistant the populace will be to paying their taxes, meaning the more military force needs to be diverted to tax collection and the greater the oppression. Taxes are required to pay soldiers and to maintain high roads, bridges, markets and other infrastructure. Merchants will prefer to travel routes which are better policed and maintained, which means more merchants trading in your markets, which means more tax.
Aristons who can generate surplus can hire more soldiers, ascend the feudal hierarchy, and wage war against neighbours.