Caravans are basically any group moving together from one location to another with goods to sell. In Revival the caravan forms a major part of the economic growth and trade between cities and provides a critical means of wealth building for players.
Caravans can be either player formed or NPC run, and can be as simple as a group of comrades moving goods to organizing large scale trade runs at the Caravan House. Caravans can be run both along ground paths as well as being taken over sea via sea-freight. The goal of the caravan is to successfully navigate from one city to the next to sell its wares, which requires careful consideration towards route and safety and provisions, as they are multiple Session journeys. A caravan should not leave without at least some combat capable members, which can also be hired at the Caravan House.
There are no limitations currently known to what a caravan can transport, but there is a potential for goods to be banned in some areas. The laws which govern that are subject to change as well, as Player Politics develop. Also while caravans can utilize a variety of wagons and carts there are still limits to the physical size and weight, as all items can cause levels of encumbrance to the travelers. Additionally the carts must be pulled by horses or other Beasts of Burden, which are not cheap themselves and can either be purchased or rented.
There are no special actions required to initiate a caravan, however those lacking appropriate members to fill the needs of their journey or who wish to join an existing planned caravan can visit the Caravan House to coordinate with other players or hire NPC's to in order to proceed.