Games & Virtual Worlds Series
Core Mechanic Systems
Understanding Games: How Video Games & Board Games Work
A game’s “core mechanics” are the information and algorithms that describe the game’s fundamental rules and internal processes with great precision.
The rulebook in a board game typically outlines the basic rules and mechanics of the game, as well as any variations or special rules that may be included. It is meant to provide players with a clear understanding of how to play the game and what is expected of them. In contrast, the core mechanics in a video game are the fundamental elements that define how the game works and how players interact with it. These mechanics can be quite complex and may involve a wide range of elements, including character abilities, game controls, and game physics.
In general, the rulebook for a board game is intended to be a concise reference for players, while the core mechanics of a video game are typically more detailed and involved. This is because video games often have more complex gameplay and a larger number of interacting elements, which requires a more comprehensive set of mechanics to define how the game works.
General Categories of Mechanics
Five distinct categories of gameplay mechanics are described by Joris Dormans and Adam Adams in their book Game Mechanics: Advanced Game Design.
Physics, or the mathematical laws of force and motion. Most video games with physics follow Newtonian mechanics, however they often simplify or change them. Cartoon physics is when a game distorts normal physical behavior, such making balls bounce higher each time they touch the ground.
Internal economies. An economy oversees the generation, consumption, and exchange of finite resources under constraints. Gold coins and popularity are examples of concrete and intangible resources, respectively.
Progression mechanics. These mechanics guide the player through a succession of tasks, each with a single solution, in a generally repeatable sequence. The user moves an avatar through a simulated area or through a virtual path as a progression of stages, where they encounter things that help them make progress, such as keys to get through doors or a handy parachute if they need to jump out of a plane for some reason.
Tactical maneuvering occurs in open or semi-open spaces. Chess, Go, and Total War use tactical maneuvering. The rules must explain what advantages each unit type gains from its position relative to another.
Social interaction rules govern player relationships, not only their speech channels. These include rules about forming alliances, team play, etc.
What Core Mechanics Do
Core mechanics are the fundamental elements that define how a game works and how players interact with it. Some of the main functions of core mechanics in a game include:
Running the game’s economy: Core mechanics can be used to define how resources are acquired, spent, and managed within a game. For example, in a strategy game, players may need to manage their resources to build and maintain a base, while in a role-playing game, players may need to manage their resources to purchase items and equipment.
Processing player inputs: Core mechanics can be used to define how players interact with the game and make decisions. This may involve defining the controls for the game, as well as how player actions affect the game world.
Changing game mode: Core mechanics can be used to define how the game transitions between different modes or phases. For example, in a real-time strategy game, the core mechanics may define how the game switches between building, attacking, and defending phases.
Timing events with progress through the narrative system: Core mechanics can be used to define how the game’s story progresses and how events are triggered. For example, in an adventure game, the core mechanics may define how the player’s actions impact the plot and lead to different outcomes.
Keeping the player challenged: Core mechanics can be used to define how the game challenges the player and keeps them engaged. This may involve introducing new mechanics or increasing the difficulty as the player progresses through the game.
In a real-time game, the core mechanics define how the game progresses in real-time, meaning that the game is constantly moving forward and players must take action as events happen. In contrast, in a turn-based game, the core mechanics define how the game progresses in turns, with each player taking a turn to make decisions and take action before play passes to the next player.
One-shot events are events that happen once and cannot be undone or repeated. They can be an important part of the core mechanics in a game, as they can add variety and challenge to the gameplay. For example, in a strategy game, a one-shot event might be a limited-time offer to purchase a powerful new unit or a surprise attack by an enemy force.
Here’s an example of how one-shot events might fit into the core mechanics of a real-time strategy game:
In the game, players must manage their resources and build an army to conquer enemy territories.
As part of the core mechanics, the game includes one-shot events that can happen at any time. These events might include things like a sudden tornado that destroys a portion of the player’s base, or a surprise attack by a rival faction.
Players must react to these one-shot events in real-time, using their resources and strategic skills to minimize the damage and maintain their advantage.
One-shot events add an element of unpredictability and challenge to the gameplay, forcing players to adapt to changing circumstances and make quick decisions.
The core mechanics of a game are the fundamental elements that define how the game works and how players interact with it. Level design, on the other hand, refers to the process of creating and arranging the levels or stages of a game.
The core mechanics of a game will have a strong influence on the level design. The specific challenges and goals of each level will often be based on the core mechanics of the game, and the layout and design of the level will often be tailored to support these mechanics. For example, in a platformer game, the core mechanics might include jumping and dodging obstacles, and the level design would need to include platforms and obstacles that challenge the player’s skills in these areas.
On the other hand, the level design can also influence the core mechanics of a game. For example, if a level introduces a new mechanic or enemy type, the player may need to learn and adapt to this new element in order to progress. In this way, the level design can help to introduce and reinforce the core mechanics of the game.
The relationship between a game’s core mechanics and level design is one of interdependence, with each element influencing and shaping the other.
Instances & Types
In a video game, resources can refer to a wide range of elements, including objects, characters, animations, sounds, and more. These resources can be organized and managed in various ways, depending on the needs of the game.
One way to categorize resources is by separating them into instances and types. An instance is a specific occurrence of a resource, while a type is a class or category of resources.
For example, consider a game that includes a variety of enemies. Each enemy might be considered an instance of the “Enemy” resource type. There might be multiple instances of the same enemy type in the game, such as multiple goblins or skeletons. However, each instance would be a unique occurrence of the enemy, with its own properties and characteristics.
On the other hand, the “Enemy” resource type would define the general characteristics and behaviors that are shared by all instances of that type. This might include things like the enemy’s appearance, attack patterns, and weaknesses.
Instances are used to represent specific occurrences of a resource in the game world, while types are used to define the properties and behaviors that are shared by all instances of that resource. This separation of instances and types can help to make resource management more efficient and flexible, as it allows developers to reuse resources and make changes to resource behavior at the type level rather than having to make changes to each individual instance.
Entities, Compound Entities, Attributes & Compound Attributes
An entity is a basic object or element that exists within the game world. An entity can be a character, a piece of scenery, a weapon, or any other object that the player can interact with or observe.
A unique entity is an entity that is distinct and individual, and cannot be easily compared or replaced with other entities. Unique entities are often used to represent special or important characters or objects in a game, and they may have unique characteristics or behaviors that set them apart from other entities.
For example, in a role-playing game, the player character might be a unique entity that is controlled by the player and has special abilities or powers. Similarly, a powerful weapon or artifact might be a unique entity that is essential to the player’s progress in the game.
Unique entities can be an important part of a game’s narrative or gameplay, as they can help to create a sense of mystery, importance, or specialness around certain characters or objects. They can also provide players with new and interesting challenges or opportunities, as they may require the player to approach the game in a different way in order to make use of their unique abilities or characteristics.
A compound entity is a more complex entity that is made up of multiple smaller entities. For example, a player character in a role-playing game might be a compound entity that is composed of smaller entities such as a character model, animations, and a set of stats and abilities.
Attributes are characteristics or properties of an entity that define its behavior and appearance in the game. For example, an enemy entity might have attributes such as hit points, attack power, and movement speed, while a weapon entity might have attributes such as damage output, range, and reload time.
Entities and compound entities are used to represent the objects and characters that exist within the game world, while attributes are used to define their behavior and characteristics. This allows developers to create and manage the various elements of the game in a structured and organized way.
Compound attributes are characteristics or properties of an entity that are made up of multiple smaller attributes. For example, an entity might have a “Health” attribute that is composed of several smaller attributes such as “Hit Points,” “Armor,” and “Regeneration Rate.”
Compound attributes are often used in games to simplify resource management and make it easier to define and modify the behavior of entities. By organizing attributes into compound attributes, developers can create more complex behaviors and characteristics for entities without having to manage a large number of individual attributes.
Compound attributes can also be used to create relationships between different attributes, allowing them to influence or depend on each other in more complex ways. For example, an entity’s “Attack Power” attribute might be based on its “Strength” and “Equipment” attributes, while its “Defense” attribute might be based on its “Armor” and “Agility” attributes.
Compound attributes are closely related to object-oriented programming, which is a programming paradigm that involves organizing code into “objects” that represent real-world entities and their characteristics and behaviors. In object-oriented programming, compound attributes are often implemented as “properties” or “fields” within an object, which can be accessed and modified using methods or functions.
Compound attributes are a useful tool for organizing and managing the characteristics and behaviors of entities in a game, and they can be implemented using object-oriented programming techniques to create more complex and flexible systems.
Some Entity Types
There are several types of entities that can be used to represent objects, characters, and other elements within the game world. These include symbolic entities, numeric entities, and NPC (non-player character) entities.
Symbolic entities are entities that are represented by a symbol or icon in the game. They are often used to represent objects or items that can be collected or used by the player, such as weapons, power-ups, or key items. For example, in a role-playing game, a sword might be represented by a sword icon, while a potion might be represented by a flask icon.
Numeric entities are entities that are represented by a numerical value. They are often used to represent characteristics or attributes of an entity, such as its strength, speed, or hit points. For example, in a strategy game, a unit’s attack power might be represented by a numerical value, while in a role-playing game, a character’s hit points might be represented by a numerical value.
NPC entities are entities that are controlled by the game’s AI (artificial intelligence) rather than the player. They are often used to represent characters in the game world who are not controlled by the player, such as allies, enemies, or quest givers. For example, in an adventure game, an NPC might be a shopkeeper who the player can buy items from, or a quest giver who provides the player with a task to complete.
Relationships Between Entities
Relationships between entities can be managed using a variety of techniques, depending on the needs of the game. Some common approaches for managing relationships between entities include:
Using parent-child relationships: In many games, entities can be organized into a hierarchy, with one entity serving as the parent of one or more child entities. This can be useful for managing relationships between entities that are closely connected, such as a character and the equipment they are carrying.
Using reference variables: Many programming languages include the concept of a “reference variable,” which allows one entity to refer to another entity. This can be useful for creating relationships between entities that are more complex or dynamic, such as a character’s allies or enemies.
Using data structures: Data structures such as lists, arrays, and dictionaries can be used to store and manage relationships between entities. For example, a list of enemies might be used to store the enemies that a player character has encountered, while an array of items might be used to store the items that a character is carrying.
To manage the relationships between quantitative and qualitative attributes of entities, game designers often use a combination of data types and data structures. For example, they might use numerical data types such as integers or floats to store quantitative attributes such as a character’s hit points or attack power, and they might use text data types or strings to store qualitative attributes such as a character’s name or description.
They may also use data structures such as dictionaries or objects to store attribute values and organize them in a way that makes it easy to access and modify them as needed. For example, a character object might include both quantitative attributes such as hit points and attack power, as well as qualitative attributes such as name and description.
Symbolic and Numeric Relationships
Numeric relationships in video games are relationships between entities that are based on numerical values or quantities. For example, in a role-playing game, a numeric relationship might be the relationship between a player character’s hit points and the damage they take in combat. If the character’s hit points are reduced to zero, they are defeated, while if the character’s hit points are above zero, they are still alive.
Symbolic relationships in video games are relationships between entities that are based on symbols or icons rather than numerical values. For example, in a strategy game, a symbolic relationship might be the relationship between different units on the battlefield. Each unit might be represented by a symbol or icon, and the specific symbol or icon used might indicate the unit’s type, abilities, or other characteristics.
There are many ways that game systems can combine numeric and symbolic relationships. One common way is to use numeric values to represent the underlying characteristics or attributes of an entity, while using symbols or icons to represent the entity itself. For example, in a role-playing game, a character’s hit points might be represented by a numerical value, while the character’s appearance and abilities might be represented by a symbol or icon.
Another way that game systems can combine numeric and symbolic relationships is by using numerical values to represent the degree or strength of a symbolic relationship. For example, in a strategy game, the relationship between two units might be represented by a numerical value that indicates the strength of the bond between them. A higher value might indicate a stronger bond, while a lower value might indicate a weaker bond.
Numeric and symbolic relationships are important tools for representing and managing the various elements and relationships within a game world. Game systems can combine these types of relationships in various ways to create more complex and dynamic gameplay.
Events & Processes
Events and processes are two different types of gameplay elements that can be used to create interactive and dynamic gameplay.
An event is a specific occurrence or situation that happens within the game world. Events can be triggered by player actions, by the game’s internal logic, or by other factors. For example, in a role-playing game, an event might be a random encounter with an enemy, a quest that becomes available, or a cutscene that plays out to advance the story.
A process, on the other hand, is a continuous or repetitive action that happens within the game. Processes can be triggered by player actions, by the game’s internal logic, or by other factors. For example, in a real-time strategy game, a process might be the building and training of units, the gathering of resources, or the movement of units across the map.
In general, events are used to create specific, one-time occurrences within the game world, while processes are used to create continuous or repetitive actions or behaviors. Both events and processes can be an important part of a game’s gameplay and can help to create a dynamic and interactive experience for players.
Conditions
Conditions are used to define when certain actions or events should happen. If/when conditions are a type of condition that specifies a specific criterion that must be met in order for an action or event to occur.
For example, an if/when condition might be used to determine when an enemy should attack the player, or when a power-up should be activated. If the specified criterion is met, the action or event will happen; if the criterion is not met, the action or event will not happen.
Conditions are often used in conjunction with other gameplay mechanics such as variables and logic statements to create more complex and dynamic gameplay. For example, a condition might be based on the value of a variable, such as the player’s health or the number of enemies remaining. Or it might be based on the outcome of a logic statement, such as whether the player has reached a certain location or completed a specific task.
Conditions allow developers to create interactive and dynamic gameplay that reacts to player actions and the game’s internal logic.
Related Articles
The Game State, Information & Movement
Chance, Probability & Fairness
Trade-Offs, Dilemmas, Sacrifices, Risk & Reward
Actions, Events, Choices, Time & Turn Taking
Ethics, Morality, Violence & Realism
Overview of Video Game Systems
Non-Core Mechanics: Progression
Non-Core Mechanics: Social Interactions
Common Digital Gaming Platforms
Bibliography & Further Reading
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- A Theory of Fun for Game Design by Raph Koster
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- Basics of Game Design by Michael Moore
- Blood, Sweat, and Pixels: The Triumphant, Turbulent Stories Behind How Video Games Are Made Blood, Sweat, and Pixels: The Triumphant, Turbulent Stories Behind How Video Games Are Made by Jason Schreier
- Board Game Design Advice: From the Best in the World vol 1 by Gabe Barrett
- Building Blocks of Tabletop Game Design: an Encyclopedia Of Mechanisms by Geoffrey Engelstein and Isaac Shalev
- Character Development and Storytelling for Games by Lee Sheldon
- Chris Crawford on Game Design by Chris Crawford
- Clockwork Game Design by Keith Burgun
- Elements of Game Design by Robert Zubek
- Fundamentals of Game Design by Ernest Adams
- Fundamentals of Puzzle and Casual Game Design by Ernest Adams
- Game Design Foundations by Brenda Romero
- Game Design Workshop by Tracy Fullerton
- Game Mechanics: Advanced Game Design by Ernest Adams and Joris Dormans
- Game Writing: Narrative Skills for Videogames edited by Chris Bateman
- Games, Design and Play: A detailed approach to iterative game design by Colleen Macklin and John Sharp
- Introduction to Game Systems Design by Dax Gazaway
- Kobold Guide to Board Game Design by Mike Selinker, David Howell, et al
- Kobold’s Guide to Worldbuilding edited by Janna Silverstein
- Level Up! The Guide to Great Video Game Design, 2nd Edition by Scott Rogers
- Narrating Space / Spatializing Narrative: Where Narrative Theory and Geography Meet by Marie-Laure Ryan, Kenneth Foote, et al.
- Narrative Theory: A Critical Introduction by Kent Puckett
- Narrative Theory: Core Concepts and Critical Debates by David Herman, James Phelan, et al.
- Narratology: Introduction to the Theory of Narrative, Fourth Edition by Mieke Bal
- Practical Game Design by Adam Kramarzewski and Ennio De Nucci
- Procedural Storytelling in Game Design by Tanya X. Short and Tarn Adams
- Professional Techniques for Video Game Writing by Wendy Despain
- Rules of Play by Salen and Zimmerman
- Storyworlds Across Media: Toward a Media-Conscious Narratology (Frontiers of Narrative) by Marie-Laure Ryan, Jan-Noël Thon, et al
- Tabletop Game Design for Video Game Designers by Ethan Ham
- The Art of Game Design, 3rd Edition by Jesse Schell
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- The Routledge Companion to Video Game Studies by Bernard Perron and Mark J.P. Wolf
- The Routledge Encyclopedia of Narrative Theory by David Herman
- The Ultimate Guide to Video Game Writing and Design by Flint Dille & John Zuur Platten
- Unboxed: Board Game Experience and Design by Gordon Calleja
- Video Game Storytelling: What Every Developer Needs to Know about Narrative Techniques by Evan Skolnick
- Writing for Video Game Genres: From FPS to RPG edited by Wendy Despain
- Writing for Video Games by Steve Ince
- 100 Principles of Game Design by DESPAIN
