Rules are like if-then statements. If you do this, then this other thing will happen. It could be a reward or a setback.
Movies, TV shows, drama, games, and all stories have rules. Rules motivate the characters, plant the clues, resolves the conflict, and so on. When stories deviate from the rules, we find them unsettling, unsatisfying, or a Lars von Trier film.
Game
Some games do not have rules, but rules usually are important. Games are experiences created by the rule systems. Stories have rules, too. Players and characters make choices that affect outcomes, and those outcomes affect further choices they can make. It's a feedback loop: rules create consequences, consequences create feelings, those feelings affect the player's next actions, and those actions are again judged by the rules. These feelings can deepen the narrative experience for the player. This is the storytelling alchemy that games can possess: a combination of gameplay and narrative.
Players will have to refer to the rule book or instruction manual during traditional gameplay, but computers can automate rules to make them almost invisible: rolling dice, doing math, keeping score, acting as a referee, and generally tracking changes in the game state (position, statistics, achievements, etc).
The first thing players discuss when starting a game are rules. Someone will explain the rules: how to move, what the cards mean, how to win, etc.
(Slay the Dragon: Writing Great Video Games by Robert Denton Bryant & Keith Giglio, 2015. Page 43-44)
Game Design: The Lens of Rules
To use this lens, look deep into your game, until you can make out its most basic structure. Ask yourself
- What are the foundational rules of my game? How do these differ from the operational rules?
- Are there "laws" or "house rules" that are forming as the game develops? Should these be incorporated into my game directly?
- Are there different modes in my game? Do these modes make things simpler or more complex? Would the game be better with fewer modes? More modes?
- Who enforces the rules?
- Are the rules easy to understand or is there confusion about them? If there is confusion, should I fix it by changing the rules or explaining them more clearly?
A game's rules are arrived at gradually and experimentally. The designer's mind generally works in the domain of "operational rules" occasionally switching to the perspective of "foundational rules" when thinking about how to change or improve the game. The written rules come toward the end, once the game is playable. Part of the designer's job is to make sure there are rules that cover every circumstance. Be sure to take careful notes as you playtest, because during these tests the holes in your rules will appear. A game is its rules - give them the time and consideration they deserve.
(The Art of Game Design: A Book of Lenses by Jesse Schell, Carnegie Mellon University, 2008. Page 150)
Game Mechanic
The rules are the most fundamental mechanic. They define the space, the objects, the actions, the consequences of the actions, the constraints on the actions, and the goals. They make possible all mechanics and add the crucial thing that makes a game a game: goals.
(The Art of Game Design: A Book of Lenses by Jesse Schell, Carnegie Mellon University, 2008. Page 144)
Parlett's Rule Analysis
David Parlett analyzed the different kinds of rules that are involved with gameplay. This diagram shows the relationships between all the kinds of rules we are likely to encounter.
- Operational Rules - "What the players do to play the game." When players understand these, they can play a game.
- Foundational Rules - The underlying formal structure of the game.
- Behavioral Rules - These are rules implicit to gameplay, which most people naturally understand as part of "good sportsmanship."
- Written Rules - The document that players have to read to gain an understanding of the operational rules.
- Laws - Tournament rules formed when the stakes are high enough that a need is felt to explicitly record the rules of good sportsmanship or to clarify or modify the official written rules.
- Official Rules - These are created when a game is played seriously enough that a group of players feels a need to merge the written rules with the laws.
- Advisory Rules - The rules of strategy.
- House Rules - "Feedback" includes house rules created by players in response to a deficiency perceived after a few rounds of play.
(The Art of Game Design: A Book of Lenses by Jesse Schell, Carnegie Mellon University, 2008. Page 144-146)
Mode
Many games have very different rules during different parts of play. Each mode may have different rules or even different GUIs. When your game changes modes in a dramatic way, it is very important to let your players know. Too many modes and the players can get confused. Often, there is one main mode with several sub-modes, which is a good hierarchical way to organize the different modes. Sid Meier proposes players should never sped so much time in a sub-game that they forget what they were going in the main game.
(The Art of Game Design: A Book of Lenses by Jesse Schell, Carnegie Mellon University, 2008. Page 147)
Enforcer
In traditional games, rules are primarily enforced by the players themselves or by an impartial referee. With computer games, the computer enforces the rules. A computer enforcer enables much more complex games now that players don't have to memorize all the rules. A rule becomes a physical constraint of the game world. Many game rules are enforced by the design of the space, objects, and actions.
The computer is best for dull rule enforcement and managing complex, subtle, and rich depths of gameplay, but the rules must never become so complex that a player can't even form a rough idea of how the game works. Make the rules something the players can discover and understand naturally, not something they have to memorize.
(The Art of Game Design: A Book of Lenses by Jesse Schell, Carnegie Mellon University, 2008. Page 147-148)
Object of the Game
The rule at the foundation of all the others: the goal. Make it concrete, achievable, and rewarding.
(The Art of Game Design: A Book of Lenses by Jesse Schell, Carnegie Mellon University, 2008. Page 148-149)