Most Sim titles require some form of resource management which is usually currency of one type or another. SimIsle has its own currency, known as the "EMU", but this is only one of the many resources available on an isle. Each island has varying deposits of natural resources such as lumber, coal, gold, iron, and oil which can be gathered by building an appropriate facility (such as a mine, logging camp, or oil rig) on a tile which contains the resource. Once the facility is built, it operates more or less autonomously and will produce the specified resource at a rate determined by various factors including the richness of the deposit in that area.
Two other important resources are food and unskilled labor, both of which are supplied by the native villages that are dotted across each island. Initially, the native villages have low populations and are only capable of producing enough food to support the lone settlement. Agents with the appropriate skills can be sent to the villages to train them which increases their ability to produce food. This, in turn, allows the village population to increase which can then be used to found new villages (to further increase food supply) or act as an unskilled labor pool.
The surplus food produced by well trained villages can be used to support populations in towns and cities (which are built by the player) which can then be used to obtained unskilled labor. Additionally, the native population has a happiness level that can be adversely affected by environmental conditions or by drawing too many unskilled laborers. Unhappy villages will sometimes start growing narcotics, as mentioned previously, which can be exploited for profit using an agent with the Criminal Contacts skill.
Most natural resources require unskilled labor to extract them so usually the first thing the player will do in a new simulation is establish an unskilled labor pool. Once that is completed facilities can be produced to extract the raw materials from the environment. Other facilities can then be built to produce lower-end goods that can be sold for profit, used in cities or used as part of the supply line in building higher end goods. The various facilities in this supply chain (except for labor sources, although cities must be connected to factories and warehouses to purchase goods from them) are connected by roads built automatically by the simulation.
An AI manages what resources are distributed where and one of the challenges of the game is balancing supply with demand. In most cases, it is also possible to simply buy equipment and goods needed to jumpstart production or build new facilities, but this is not recommended for the long haul since it is expensive and must be performed manually by the player. Idle facilities that are starved because resources are not distributed to them or simply because none are available can become quite costly. Most resource deposits do not provide infinite supplies and so can be exhausted with time, which means most supply chains can not function without player interaction forever nor can a single simulation indefinitely support heavy industry.
Another interesting resource in the game which proves to be reasonably lucrative and enduring is tourists. Various facilities can be created that bring tourists to the island such as airports and ferries, and they act in a manner similar to other resource sources like mines (although the "used up" tourists are returned then, unlike mines). The next facility in the tourism supply line is tourist accommodations which can be upgraded both in size and quality and produce income. From there tourists will visit tourist attractions that can both be built and also discovered in the jungles by using an Agent with the exploration skill. Attractions not built by the player will often have to be opened to the public explicitly by the player and then upgraded before they become effective in drawing tourists and producing income.