Whether you have a ground-breaking unique puzzle mechanic nobody has ever seen before or are reinventing some tried-and-true classics like a block-pushing game, how you choose and use your puzzle mechanics is what will make your game shine. 

Mechanics

A game’s mechanics are the ways the player and game interact. The Witness’s main mechanic is mazes; Hue’s is changing the background colour, Portal’s is portals.

Great mechanics lead to great puzzles, and the best mechanics are usually simple but profound. Portal’s portals – which allow the player to teleport to places they otherwise could not reach – is a simple idea, yet it opens up lots of potential. Portals feel intuitive and fun. Once you understand the idea of a portal, you can immediately imagine endless possibilities for them,

Primary and Secondary Mechanics

A puzzle game usually has one main mechanic  – the primary mechanic, and many puzzle games have a number of secondary mechanics that complement the primary mechanic. The primary mechanic is usually what makes the game unique and special.

A great example of a primary puzzle mechanic is Portal’s primary mechanic – portals. Most – if not all – the puzzles in the Portal games use the portal mechanic. In the Portal games, one of the secondary mechanics is a laser beam. When combined with portals, the laser beams take on new behaviour – instead of the laser beams travelling in a straight line, they can be made to change direction by shooting them into a portal and out of another portal elsewhere.

Secondary mechanics can be anything, and there are plenty of classic mechanics that can be added to just about any puzzle game, for example boxes, switches, and even movement mechanics like jumping. The key is to choose mechanics that fit well with your primary mechanic.

Gameplay Actions as Mechanics

Actions are the ways the player interacts with the game. An action in Chess is moving a piece. In a shooter game the actions would be running, shooting, picking up objects, etc. There is some potential overlap between actions and mechanics that can inform how you build your puzzles. 

In a physics puzzle game like my own Game of Clowns, where the player puts objects into the scene to influence the physics simulation when the level is started with the aim of achieving a particular goal (e.g. make a clown fall into a barrel of water). The player’s actions are quite simple:

• place/move objects
• rotate objects

These actions are as important as the mechanics in this particular game, as the puzzles are heavily reliant on the placement and rotation of the objects.

Another action in Game of Clowns is the Play button that the player presses when they with to run the physics simulation to see if they have solved the puzzle. This action is not comparable to a mechanic, as it has no strategic function.

When an action is treated like a mechanic, it will usually fall into the secondary mechanic category. Going back to the puzzle platformer example, jumping may be used to add to a puzzle’s difficulty or complexity, but is usually not going to be used as the puzzle’s primary challenge.

Types of Mechanics

Mechanics have inherent ‘possibility spaces’ that measure the range of their possible states or uses. I find it useful to think of mechanics as being either analogue or digital depending on their possibility space.

Analogue Mechanics

Analogue mechanics are mechanics that have a free-form aspect to them. Portal’s portals can be placed at any arbitrary position in the puzzle level, creating almost limitless choice for the player.

An Analogue Mechanic Example

An excellent example of an analogue mechanic is physics. Realistic physics makes a game intuitive and fun, and is perhaps the ultimate analogue mechanic. My game Game of Clowns is an Incredible Machine style physics puzzle game where the player adds objects to the scene to influence a physics simulation to achieve a goal (in this level the goal is to get the balloon to float off the top of the screen):

The player has the freedom to place objects anywhere on the screen, they are not constrained (and can’t use the constraints to narrow down the solution). The player must take the physics behaviour of the objects into account, including the objects already in the level and those available to the player to add.

The freeform analogue mechanic forces the player to think about the consequences of their actions. They are not given a simple set of options to choose from. Choosing whether a switch is on or off is too simple to present an interesting challenge; on the other hand, giving the player full control over where an object is placed forces them to think.

Some mechanics that fit in the analogue category:

• Portals (can be placed always anywhere)
• Boxes (can be placed anywhere and used in different ways)
• Physics puzzle games where you can place objects anywhere on the screen to influence realistic physics

Digital Mechanics

Digital mechanics have a fixed, limited number of states, such as an on/off switch or push button. They give the player more concrete choices, but limit the variety and possibilities available. They have a limited possibility space.

Some examples of digital mechanics:

• On/off switches and buttons
• Keys and locks

Digital Mechanics Notes

When you use digital mechanics, make sure you don’t create frustrating puzzles that are difficult not because they are challenging but because they must be solved with trial-and-error instead of insight or intelligence.

Imagine a puzzle where you need to set four switches into the following configuration:

This puzzle is complex, but it isn’t challenging or fun. The player has to try all the switches in every combination until they get it right. The player doesn’t have any interesting or challenging decisions to make, just a series of on/off choices.

One way to make a puzzle like this work is to combine it with another element. For example, in a detective style game, you could have the solution to the switch puzzle encoded somewhere else, for example in morse code written in a notebook. This avoids trial-and-error style puzzle solving by turning the puzzle into something more like a pattern-matching problem that will make the player feel clever when they realise that the dots and dashes of the morse code correspond to the power state of the four switches.

Complementary Mechanics

While analogue mechanics are generally more interesting, flexible, and effective than digital mechanics, it’s not a hard-and-fast rule to prefer them. Some great puzzle games have a digital mechanic at their heart or a set of digital mechanics that together form a great complexity that leads to great puzzles. Chess is a great example of a game that has very finite, simple rules that could be described as digital mechanics, but the interaction of these simple choices, and the large number of choices on every turn lead to massive complexity and strategic potential.

Choosing Complementary Mechanics

Analogue mechanics provide the best challenges and scope for variety. Digital mechanics tend to lead to trial-and-error solutions or overly simplistic puzzles. Complexity with digital mechanics tends to come from adding multiple simple choices together rather than asking the player to think through a more open-ended problem as they would with an analogue mechanic.

Your primary mechanic should usually be an analogue mechanic with a large range of potential states. This not only makes your puzzles more interesting and varied, but it also makes your player feel that they have freedom, and will make your player feel smart when they solve your puzzles. If you think of any great puzzle game it will almost certainly have an analogue  primary mechanic.

Your secondary mechanics can be anything. The important thing is that they work well with the primary mechanic, either thematically or in how they enable you to create interesting and fun puzzles.

Secondary Mechanics Affecting the Primary Mechanic

One way a secondary mechanic can work is by blocking the primary mechanic. In The Swapper, the player can clone themselves and ‘shoot’ their consciousness (i.e. control) between their clones. Coloured light in the puzzle blocks the cloning and consciousness transferral in different ways, which forces the player to work around this hindrances to solve puzzles.

Portal uses mechanics that work well with the core mechanic rather than limiting it. Laser beams can shoot through the portals to reach their destination; and the player can pass cubes through portals. This technique make an otherwise simple mechanic far more interesting by forcing the player to use the main mechanic in varied and interesting ways. The player needs to think about how each of the secondary mechanics works with and is affected by the portal mechanic.

Matching Mechanics

If you’re making a puzzle game you probably started with your primary mechanic idea, as that is the cornerstone of a puzzle game.

Two great ways to come up with secondary mechanics are thinking mechanically and thematically. I use typical brainstorming techniques to help find ideas.

Thematic Mechanics

Your game’s theme can help you with deciding on your secondary mechanics. In Game of Clowns, I thought of everything to do with circuses to find good mechanics, and then thought about how each could work in a physics-based puzzle game. I ended up with a combination of mechanics that felt at home in a circus themed game. In Game of Clowns, you can shoot a clown from a canon and watch him bounce off a trampoline, knock another clown off a platform, then fall into a barrel of water to solve a puzzle. Every aspect fits thematically.

Portal has a science-fiction theme, and the secondary mechanics are mostly also science-fiction themed – e.g. laser beams and light ‘bridges’. You can look to existing games for inspiration and adapt their mechanics to suit your game’s theme. For example, in an animal-themed puzzle platformer you might replace crates with animals you can climb on. Perhaps you could make it so the player needs to use food to lure the animal to the correct position instead of pushing a box.

Mechanical Mechanics

To match mechanics mechanically, simply look for mechanics that work well together. This is a great time to look at the classics – boxes that can be pushed around or jumped on, power switches, moving platforms, etc. There is no shame in looking at other games for ideas. Most secondary mechanics are pretty common, and they are common because they are versatile and intuitive.

Portal’s companion cube (which is really just a box) is a very unoriginal generic mechanic, but it works well within the game. The box effectively takes on new properties when used with portals. Portals and boxes complement each other.

As a game developer, it’s also important to be unafraid to change your mind about any aspect of your game. If you find that you come up with a great new mechanic that doesn’t fit with your theme – change your theme! Game of Clowns started life with a caveman theme until I found that fun physics mechanics suited a circus theme better. For puzzle games in particular, the mechanics are the game. Don’t be precious about your story or theme at the expense of your mechanics.

Be Tough

Following on from the above paragraph, it’s also important to be tough when it comes to editing your ideas. Don’t push on with a mechanic that isn’t working, as it will lead to poor puzzles and frustration (for both you and your players).

In my game Mouse Dreams, I ended up removing a mechanic from the game late in development because it just wasn’t fun, and didn’t add anything to the game that couldn’t be achieved in a simpler way. That mechanic might be useful in a different game, and I have already been thinking of ways it could be used that work better.

Mechanics Cheat Sheet

• Have a strong core mechanic – preferably something profound and intuitive (e.g. Portal)
  • If you can easily think of 10 puzzle ideas with your mechanic it’s probably good.
• Analogue mechanics are generally more interesting than digital ones, especially for your primary mechanic
• Choose secondary mechanics that complement the core mechanic.
• Avoid giving the player simple decisions.
• Make simple mechanics more interesting by combining them with other mechanics.