Engine Building

Intent
A significant portion of gameplay is dedicated to building up and tuning an engine to create a steady flow of resources.

Motivation
A Dynamic Engine, Converter Engine, or a combination of different engines form a complex and dynamic core of the game. The game includes at least one, but preferably multiple, mechanics to improve the engine. These mechanics can involve multiple steps. For the engine building pattern to generate interesting gameplay, it should not be trivial for the player to assess the state of the engine.

Applicability
Use engine building when:


 * You want to create a game that has a strong focus on building and construction.
 * You want to create a game that focuses on long-term strategy and planning.

Structure


Note: The structure of the core engine above is an example. There is no fixed way of building the engine. Engine building requires only that several building mechanics operate on the engine and that the engine produces energy.

Participants

 * The core engine usually is a complex structure combining multiple engine types.
 * At least one, but usually multiple, building mechanisms to improve the core engine.
 * Energy is the main resource produced by the core engine.

Collaborations
Building mechanisms increase the output of the engine. If energy is required to activate building mechanisms, then a positive, constructive feedback loop is created.

Consequences
The engine building increases the difficulty of a game. It is best suited to slower-paced games because it involves planning and strategic decisions.

Implementation
Including some form of unpredictability is a good way to increase difficulty, generate varied gameplay, and avoid dominant strategies. Engine building offers many opportunities to create unpredictability because the core engine tends to consist of many mechanisms. The complexity of the core engine itself usually also causes some unpredictability.

When using the engine building pattern with feedback, it is important to make sure the positive, constructive feedback is not too strong and not too fast. In general, you want to spread out the process of engine building over the entire game.

An engine building pattern operates without feedback when energy is not required to activate building mechanisms. This can be a viable structure when the engine produces different types of energy that affect the game differently and allows the players to follow different strategies that favor particular forms of energy above others. However, it usually does require that the activation of building mechanisms is restricted in some way.

The upgrade mechanism in a Dynamic Engine pattern also is an example of a building mechanism. In fact, the Dynamic Engine is a simple and common implementation of an engine building pattern. However, its simplicity means that a Dynamic Engine allows only one or maybe two kinds of upgrades. The typical core engines in a game that follow the engine building pattern allow for many more upgrade options.

Examples
SimCity is a good example of engine building. The energy in SimCity is money, which is used to activate most building mechanisms. The mechanisms consist of preparing building sites, zoning, building infrastructure, constructing special buildings, and demolition. The core engine of SimCity is quite complex with many internal resources such as people, job vacancies, power, transportation capacity, and three different types of zones. Feedback loops within the engine cause all sorts of friction and effectively balance the main positive feedback loop, up to the point that the engine can collapse if the player is not careful and manages the engine poorly.

In the board game Puerto Rico, each player builds up a New World colony. The colony generates different types of resources that can be reinvested or converted into victory points. The core engine includes many elements and resources such as plantations, buildings, colonists, money, and a selection of different crops. Puerto Rico is a multiplayer game in which the players compete for a limited number of positions that allow different actions to improve the engine; they compete for different building mechanics. This way, a strong multiplayer dynamic is created that contributes much of its gameplay.

Related Patterns
the difficulty of the engine building pattern. by an implementation of engine building that consumes energy to activate building mechanisms. building pattern.
 * Applying multiple feedback to the building mechanisms is a good way to increase
 * All friction patterns are suitable to balance the typical positive feedback created
 * The dynamic engine is one of the simplest possible implementations of an engine
 * The engine building pattern elaborates the dynamic engine and converter engine patterns.
 * The engine building pattern can be elaborated by the worker placement pattern.