Slow Cycle

Intent
A mechanism that cycles through different states slowly, creating periodic changes to the game’s mechanics.

Motivation
By introducing a slowly operating mechanism outside the player’s control, the game’s economy shifts between different phases. This requires players to adapt and develop more versatile strategies.

Applicability
Use a slow cycle when:
 * You want to create more variation by introducing periodic phases to the game.
 * You want to counteract the dominance of a particular strategy.
 * You want to force players to periodically adapt strategies to shifting circumstances.
 * You want to require a longer period of learning before achieving mastery of the game. (Players experience slow cycles less frequently, so have fewer opportunities to learn from them.)
 * You want to introduce subtle, indirect strategic interaction by allowing players to influence the cycle’s period or amplitude.

Structure


''Note: The structure here is just an example. There are many different ways to build slow cycles, and there are many ways it can affect other game mechanisms.''

Participants

 * A slow cycle mechanism oscillates between two (or conceivably more) states.
 * The affected mechanism depends on the state of the slow cycle.

Collaborations
The state of the slow cycle interacts with the affected mechanism.

Consequences
The effects of a slow cycle are often hard to see, especially for new players. This creates a long learning curve that might aggravate the difference between more and less experienced players.

In most cases, players have little, if any, impact on the slow cycle mechanism. This means that it is important to communicate the current state of the cycle clearly to the player. Slow cycles that cause seemingly random changes to the game economy are generally not considered to be fair.

Implementation
There are many ways to implement slow cycles. A slow cycle might alternate between two binary states (for example, it might activate or deactivate another mechanism periodically), or it might shift between two states more gradually.

It is best if a slow cycle affects all players equally. This tests the players’ ability to predict and prepare for phase shifts in the game’s economy. In the context of a game world, slow cycles can easily be characterized as changes in the seasons, tides, or business cycles beyond the control of the players.

Slow cycles can be made less deterministic by introducing random periods in the cycle. This requires players to pay more attention to the current state of the cycle. Another way to make cycles less deterministic is by randomizing the amplitude of the cycle. For example, a slow cycle might produce some sort of energy for a short period every ten turns. In this case, either the short period can be randomized or the number of resources can be randomized without affecting the cycle’s rhythm.

Examples
StarCraft II uses a variety of different slow cycle mechanisms in different levels.

In the board game Caylus, the players build a castle and the accompanying town. The game is divided into three phases, and at the end of each phase players are rewarded for their contribution to the castle or penalized for the lack thereof. The three phases create a subtle slow cycle mechanism. Players need to plan their contributions carefully, especially because the players are also competing to place their workers to harvest the resources needed to help build the castle (Caylus also implements the Worker Placement pattern). In addition, the combined actions of the players might speed up or slow down the current cycle. Being able to predict the cycle and how it affects the plans of other players is an effective but advanced strategy in this game.

Related Patterns

 * A slow cycle elaborates the Static Engine, Static Friction, and Stopping Mechanism patterns.
 * Because a slow cycle causes shifts in the game’s economic phases, it combines well with the Worker Placement pattern to allow the player to respond to these shifts.