Mechanical Layers in Games

Analyzing games is an important part of being a game designer. In this post, I would like to propose an approach to discussing game mechanics.

Game mechanics have been researched and analyzed extensively by various researchers throughout the years. The Art of Game Design (Jesse Schell, 2008), a great introduction to the world of game design, dedicates quite a few chapters to establishing terminology around game mechanics. Game Mechanics: Advanced Game Design (Ernest Adams and Joris Dormans, 2012) digs deeper into the core of digital simulated experiences and Building Blocks in Tabletop Game Design (Geoff Engelstein and Isaac Shalev, 2019), is an extensive taxonomy of hundreds of board game mechanisms.

“Mechanics are the various actions, behaviors and control mechanisms afforded to the player within a game context. Together with the game’s content (levels, assets, and so on) the mechanics support overall gameplay dynamics.”

MDA: A Formal Approach to Game Design and Game Research, by Robin Hunicke, Marc LeBlanc, and Robert Zubek (2004)

The MDA framework (Robin Hunicke, Marc LeBlanc, Robert Zubek, 2004) defines the relationships between three concepts: Mechanics, Dynamics and Aesthetics. It argues that game rules (Mechanics) generate player behaviors (Dynamics), which evoke emotional responses in the players (Aesthetics). While game designers tinker directly with the game mechanics, players usually encounter the aesthetics of the game first. Understanding this relationship between designer and player helps us develop techniques for iterative design and game criticism.

Layers of Mechanics

In this write-up, I would like to elaborate upon the concept of game mechanics. My intention is to help people identify and evaluate the different layers of mechanics separately when analyzing games. Those three layers are Goal, System, and Data, and by separating them you’ll hopefully be able to more easily point to the experiences they create.

Goal

The goal layer contains the mechanics that contextualize player performance in the game. A game without a goal is sometimes considered as a “toy”, a “sandbox game”, or — in classical academic terms — “Paidia” (See: Man, Play and Games by Roger Caillois, 1958). The goal is represented as the rules that define the player affiliations, the victory condition, and what triggers the game end. The purpose of this layer is to establish the conflict and to drive player decisions.

• Player affiliation: Are players competing against each other? Do they win or lose as a team? Is there more than one team present in the game? Can there be more than one winner? Can everyone lose? Etc.
• Victory: The win and lose conditions for the game. It may involve leading in victory points, accomplishing certain feats, eliminating other players, surviving for long enough, and more.
• Game End: The rule that governs when and how the game ends. Is it after a set number of rounds? When certain conditions are met? Are there multiple end-game triggers? The game end can be tied to the victory condition, e.g. a race.

Example:

“A player wins when they manage to threaten the enemy king piece without it being able to escape.”

— Someone in the Sasanian Empire, around 700 A.D

The goal layer creates a focal point for the game and serves as a reference point for the players. It sets the stakes and forms the way you evaluate the game state and the other players.

System

The system layer establishes the action space available for players and determines how they are allowed to operate within it. The purpose of this layer is to enact the laws of the game world and to define its boundaries.

• Structure: How players perform actions and when they may perform them. Is the game played in turns or in real-time? Is turn order fixed or is it dynamic? Are rounds played simultaneously? Is the game split into different phases?
• Logic: The interconnected cogs that form the basis of the game’s simulation and the different spaces that define its borders: Decks of cards, play areas, tracks, player hands, resource pools, locations, and other entities, and the way they behave and interact with each other.
• Actions: The things players are allowed to do within the confines of the game and the way they interact with its logic through the use of “verbs”. (see: The Difference Between Actions and Verbs by Tadhg Kelly, 2012).

Example:

“During their turn, a player may move one piece. If your piece lands on an enemy piece, it is captured.”

— Probably the same person from before.

The system layer is what people sometimes refer to as the “core” of the game. It determines the verbs that players use when interacting with the physical game world: drawing, flipping, tapping, rolling, collecting, discarding, marking, placing, etc., and establishes the type of interactions they may have with each other and with the game spaces: combat, auction, trade, movement, activation, comboing, testing, voting, and others.

Data

The details, metrics, and exceptions that exist within the game. The number of cards in a deck, The symbols on a die, the special ability of a faction, and so on. The purpose of this layer is to seed the game’s economy and to establish evaluable game states.

• Numerical Values: The shooting range of a character, the number of points required to win, the cost of a building, etc.
• Rule Exceptions: (special effects, rule modifiers, alternate win conditions, etc.
• Game Setup: levels, scenarios, Chosen factions, the game’s ‘seed’, etc.

Example:

“The Bishop can only move diagonally, but the knight can jump over other pieces! Isn’t that neat?”

— Guess who.

The data layer contains much of the flavor of the game. These are the values that designers tweak to make the game feel “just right”, and as they are based on the system, they are usually the last to be locked in place when designing a game.

Some examples

Goal as a variable: What happens when we change only the goal layer of a game? In board games, this is usually referred to as a “variant”, and in video games, it’s a “mode”. Take these two Overwatch modes for example:

• “Assault” is an asymmetric team-based mode that sees one team trying to capture an objective from the other one.
• “Deathmatch” sees players compete individually and the player with the most kills win.

The modes feel vastly different because their goal layer is different. In “Assault” there are two major affiliations, but in “Deathmatch” each player has an individual one. The system layer remains the same; This is the same world with the same laws. players can still do the exact same actions and their interaction with the game hasn’t changed at all. You can still select your character, use cool abilities, and shoot baddies. The data layer is also the same — The character abilities and stats don’t change, and the two modes can even be played on the same map.

System as a variable: When we try changing the system of a game, we may end up with vastly different experiences. The system serves as the interface through which players interact with the game, so changing it means changing the fundamental laws of the game world. Imagine opening the box of Catan (Klaus Teuber, 1995) for the first time and finding that the majority of the rules are missing. The only known rule is that the winning player is the first to reach 10 points. Still wanting to play, you try to design a game based on the game components you find. The closest examples I could think of from real life is 7 Wonders: Duel (Antoine Bauza, Bruno Cathala, 2015), an adaptation of its predecessor 7 Wonders (Antoine Bauza, 2010), that I can imagine emerged as a re-conceptualization of the latter’s basic goal and data layer.

Data as a variable: Changing the data of the game but keeping its systems intact is something that happens quite often in games: When you play different levels, use different avatars, or try different squad compositions. Randomly generated content is a great way to increase the game’s replayability. Balance changes, season passes, and re-implementations are all based on keeping the goal and system layer intact. A great example is the stand-alone expansion to the zombie apocalypse simulator Dead of Winter (Jonathan Gilmour, Isaac Vega, 2014). Dead of Winter: The Long Night (Jonathan Gilmour, Isaac Vega, 2016) replaced almost all of the original game’s content, but despite some optional new core mechanics, it plays exactly the same.

Adding mechanics: Adding to the goal, system or variable layers usually happen in the form of game updates, DLC, and expansion packs. Many business models thrive on adding game modes (goal layer), systems (system layer), and content (data layer) to provide different experiences to their players.

Summary

• Goal — The victory condition, end game trigger, and player affiliations that drive the conflict in the game.
• System — The game’s structure, logic, and the action space that’s available for players.
• Data — the details, values, and exceptions that seed the game’s economy and establish evaluable game states.

Closing Thoughts and a short exercise

The system and its data form the game’s simulated space, and the goal informs the decision-making within it. Together they create the dynamics of the game, which evokes an experience. Even small changes in any part of the game’s mechanics can push the dynamics, and thus the experience, to be drastically different.

Here’s a short exercise:

1. select a game you enjoy;
2. Identify what its main aesthetic values are, for you (you can use the ones listed in the MDA paper: 1. Sensation; 2. Fantasy; 3. Narrative; 4. Challenge; 5. Fellowship; 6. Discovery; 7. Expression; 8. Submission);
3. Identify its goal, system, and data layers;
4. How does each of the game layers contributes to, or detracts from the aesthetics you identified?

Appeared in this article (in order):

For further reading:

• The Art of Game Design, Jesse Schell (2008)
• Game Mechanics: Advanced Game Design, Ernest Adams and Joris Dormans (2012)
• Building Blocks of Tabletop Game Design: An Encyclopedia of Mechanisms, Geoff Engelstein and Isaac Shalev (2019)
• Man, Play and Games, Roger Caillois (1958, translated by Meyer Barash)
• MDA: A Formal Approach to Game Design and Game Research, Robin Hunicke, Marc LeBlanc, Robert Zubek (2004)
• The Difference Between Actions and Verbs, Tadhg Kelly (2012)

For further playing:

• Tzolk’in: The Mayan Calendar, Simone Luciani, Daniele Tascini (2012)
• Overwatch, Blizzard Entertainment (2015)
• Catan, Klaus Teuber (1995)
• 7 Wonders: Duel, Antoine Bauza and Bruno Cathala, (2015)
• 7 Wonders, Antoine Bauza (2010)
• Dead of Winter: A Crossroads Game, Jonathan Gilmour and Isaac Vega (2014)
• Dead of Winter: The Long Night, Jonathan Gilmour and Isaac Vega (2016)