Choice, Randomness and Interaction: The Building Blocks of Game Rules

A game’s rules can be broken down into three major aspects: choice, randomness, and interaction. By further analysis of these aspects, game design, as a practice, can gain a greater understanding of its formal systems and mechanics. This paper aims to present a clear dichotomy of the different subtypes of rules within each of these aspects.

Games could be considered a series of branching nodes, which explore all the possible states that a game can be in, the game space. The rules give the players a means of exploring this space and determine which nodes can be linked and which cannot.

One method of exploring the game space is that of choice. Choice allows the players to directly govern their route through the game’s nodes. It is possible to group choice based rules in two ways.

• To do or not to do: Where there is an option to do something, but it is not a necessary action.
• Between multiple options: Out of a number of options you can perform a limited subset of those options.

Alternatively.

• Limited by game state: The options available are limited by the current state of the game.
• Consistent throughout game: The options available are consistent throughout the game.

The other main method for exploring the game space is randomness. This method sends players on new and unknown routes though the game space. Randomness can be divided into two sets with two methods. Considering how the outcome of the random event is created:

• Isolated randomness: Previous random events do not affect the current random event.
• Recursive chance: Previous random events change the odds of the current random event.

Alternatively by considering which players the random event affects.

• Shared randomness: All players are equally affected by the random event.
• Individual randomness: The random even affects only a single player.

Interaction is different to choice and randomness as a way of affecting players’ exploration of a game space. Interaction has the same affect as limiting, expanding or changing another player’s future options.

• Direct interaction: A player’s action directly affects another player.
• Indirect interaction: A player’s action indirectly affects another player.
• Verbal interaction: Players discuss game related issues with each other.

Taking choice randomness and interaction as the building blocks of games it is possible to construct many different game types. However, it is an interesting exercise to determine the different combinations of these building blocks in their simplest forms.