Static Engine

Intent
Produces a steady flow of resources over time for players to consume or to collect while playing the game.

Motivation
A static engine creates a steady flow of resources that never dries up.

Applicability
Use a static engine when:


 * You want to limit players’ actions without complicating the design. A static engine forces players to think how they are going to spend their resources without much need for long-term planning.

Structure


Note: A static engine must provide players with some options to spend the resources on. A static engine with only one option to spend the resources on is of little use.

Participants

 * Energy that is produced by the static engine
 * A source that produces energy
 * Actions the player can spend energy on

Collaborations
The source produces energy at a fixed or an unpredictable rate.

Consequences
The production rate of a static engine does not change, so the effects of the engine on game balance are very predictable. A static engine can be the cause of imbalance only when its production rate is not the same for all the players.

A static engine generally does not inspire long-term strategies: Collecting resources from a static engine, if possible at all, will be quite obvious.

Implementation
Normally, it is simple to implement a static engine: A single source that produces the energy will suffice. It is possible to add multiple steps in the energy production, but in general this will add little to the game.

A static engine can be made unpredictable by using some form of variation in the production rate. An unpredictable static engine will force the player to prepare for periods of fewer resources and reward players who make plans that can withstand bad luck. The easiest way to create an unpredictable static engine is to use randomness to vary the output level of resources or the length of time between moments of production, but skill or multiplayer dynamics could work as well.

The outcome of random production rates can be, but does not need to be, the same for every player. By using an unpredictable static engine that generates the same resources for all players, the luck factor is evened out without affecting the unpredictability. This puts more emphasis on the planning and timing that the pattern introduces. An example would be a game in which all players secretly decide how many resources all players can get. The lowest number will be the number of resources to enter play for everyone, while the players who proposed the lowest can act first. This would automatically set up some feedback from the game’s current state to this mechanism. (This system discourages inflation.)

Examples
The energy produced by the spacecraft in Star Wars: X-Wing Alliance is an example of a static engine. The energy can be diverted to boost the player’s shields, speed, and lasers. This is a vital strategic decision in the game, and the energy allocation can be changed at any moment. The amount of energy generated every second is the same for all spacecraft of the same type.



In many turn-based games, the limited number of actions a player can perform in each turn can be considered a static engine. In this case, the focus of the game is the choice of actions, and generally players cannot save actions for later turns. The fantasy board game Descent: Journeys in the Dark uses this mechanism. Players can choose between one of three actions for their hero every turn: move, attack, or prepare a Special Action (see below). In our diagram, a player gets two actions every turn and can perform the special action only once per turn. This creates five possible combinations: The player can attack twice, move twice, attack and move, attack and do a special action, or move and do a special action.



Related Patterns

 * A weak static engine can prevent deadlocks in a Converter Engine.
 * A static engine can be elaborated by a Dynamic Engine, a Converter Engine, or a Slow Cycle pattern.