An online/mobile expertise since 1998, Oscar Clark is the Evangelist for gameplay video sharing tool Everyplay from Applifier.Building fun into a game has a lot to do with understanding the balance between the familiar and the surprising.

We need our playing mechanics to be intuitive so players will engage quickly and at the same time we need them to be endlessly repeatable without becoming boring.

This is especially challenging for freemium games where we want to attract the widest audience and maintain their interest for many months of play.

We call this core mechanic the compulsion loop.

In a fantasy game this might have us fighting a monster, killing it to get treasure, then spending your winnings to improve your ability to fight the next (bigger) monster.

Each genre has its own loops – from preparing your car, winning the race and spending your winnings, to planting your crop, harvesting it and building a larger farm/city. The more familiar the loop, the easier it is to understand the concept of a game and for us to start to play.

More than that, a well-known brand or familiar art style helps us break down barriers to players trying our game in the first place and – assuming the game is consistent with that brand – this can help maintain players interest, and help convert them to paying.

However, if we are not building on that familiarity with something new, something unexpected, players can quickly become bored and leave.

The uncertainty principle

Of course, we can try to sustain interest by creating friction – introducing artificial time delays or gradually increasing the level of challenge – but over time these variables will either be mastered or become so difficult that it seems pointless to continue playing.

We need more than 'drag' to slow us down in the game, we need uncertainty and the potential for surprise.

This kind of uncertainty needs to build our expectation. It needs to demonstrate the potential to reveal new elements or strategies from just outside the expected constraints of the game.

We need to foreshadow expectations of change that players are able to reveal, which will empower them to enjoy the game more. Better still we need to create moments for the player to remember and share that makes the experience their own story.

Here are three examples of how game developers try to use this way of thinking:

Easter Eggs are probably the simplest of these techniques to introduce. They involve the placement of incongruous items in places that players need not explore to complete the game or which require extra skill to access.

These elements work best when they satisfy a different reward behaviour than the rest of the game.

For example, in a game where players are expected to compete for speed, adding a 'collecting' element such as an easter egg can offer a different strategy for 'completer-finisher' players, allowing them to gain additional pleasure by being the ones to locate all of them.

Indeed even your more typical players will still gain a sense of 'being on the inside' when they find such items, building on their sense of identification with the experience, especially if it's known that this takes skill and ingenuity to find.

Emergent behaviour is a little more tricky and often arises by accident rather than design. These are typically a tangential way for the player to play and gain enjoyment from the game, differently from the way the designers had intended.

Examples include how players decided to recreate the Mona Lisa in FarmVille or how in the early days of PlayStation Home players exploited snags in the collision-layers in some of the public spaces; allowing them to appear as if floating in the air.

Emergent principles can also be built into the flow of play to build up new strategies.

Typically, we use 'soft variables', those factors which contribute indirectly to success, but can add flavour. For example, in a level-based puzzle game, the soft variable might be things like how fast we complete it, whether we explore every corner of it or whether we used all of the power-ups/boosts available to us.
Plants Vs. Zombies used this principle to beautiful effect where they gave out achievements for self-restricting your options when completing a level – for example, if I used no mushrooms in a night time scene.

This doesn't even have to be a deliberate choice. Think about how a shotgun behaves differently from a sub-machinegun in a shooter game. Even if they deliver the same damage per second, the shotgun does this in infrequent bursts while the SMG delivers a continuous stream of bullets which instead increases your chances to hit.

Each weapon's style creates a different strategy of play, either of which may better suit the player.

Imbalanced economies require a relationship between each of the different elements a player needs to progress in the game.

So, we might start with an amount of money, storage capacity and a rate at which we can interact with the world. As we play the game we earn money we can spend on gathering or improving resources and then resell them to gain more money.

However, the rate at which we can interact with the world limits how quickly we can gain resources – unless we spend more money on upgrades. Then our limit becomes our storage space, which again needs money to improve. The same logic can apply to how we use XP/equipment/potions in a combat game, etc.

Games such as Clash of Clans are masters at using the imbalanced economy to create deeper engagement for players, making it so that each success introduces a new challenge for the player which continues their desire to play.

Word of mouth

There isn't enough space here to do these techniques full justice. However, I hope I have shown how this thinking can be applied to almost any game and deliver greater longevity to your title.

More importantly, I hope I've demonstrated how they can create moments that make the game special to each player. We need these soft variables to give players' choices meaning – not just to sustain their engagement over time but to create events which are theirs and that they will want to share with others to express why they love your game.

If we do that, then we can count on uncertainty to bring new players and longevity to our games.
To find out more about what Oscar's evangelising, visit the Everyplay website. To find out more about Oscar's minute-by-minute existence, follow him on Twitter.