Emergence, Surprises and Chaos

A game’s interest curve is the roller coaster that maintains the engaging experience. However, the unique moments that remain memorable as proof of the meaningful time players had can only happen when we make a system that can play with itself as much as humans can play with the system.

Emergence is a concept used in game design to describe moments that happen without designers planning them to. A unique scene triggered by the relationship between game and player action, emergence can be achieved by having a big number of elements with simple events that can have their outcome affected in many different ways by other objects, variables and events in the game.

A good example of an element with high emergence potential would be a sphere with real-time physics simulation affecting it. Such an object would be susceptible to all sorts of impacts and the outcome of how far it’d go would depend on the strength of each force applied to it.

Emergence is about the possible interactions versus the amount of events and nuances required to such. One event that only happens in one way, without external variables, is much less emergent than one that depends entirely on the state of the things around it.

My currently nameless (yes, it is still unnamed) top down action game puts players in the shoes of a necromancer. He’s the bringer of chaos. That is what I intend them to feel, and because of it, emergence is specially important.

Demons, which I’ve talked about in the previous article, move waves of Paladins around with their special abilities. The amount they manage to affect and the location they end up at will determine, for example, their next targets (depending on the Demon type, it could be the closest or farthest Paladin, as well as everything around the target).

Then we have Breakable Environment Objects, which take damage as they collide strongly with other objects or are attacked and cause an area effect when their constitution is below 0. Vases apply Fire, which burns and are passed to objects near those being affected. Barrels explode, sending everything flying away to potentially collide with other objects. Fences simply break, but that means leaving an open cliff from which elements can fall to their demise.

There are moments, however, that emergence has to be controlled. This happens to reduce the amount of situations that would compromise your game’s intended experience, such as dominant strategies or undesired exploits. In order to do that, it is necessary to spot the most significant aspect of an event and how affecting other objects could disrupt the system’s intent.

Back to our nameless game, what we don’t want to happen is have the necromancer’s undeads lose their efficiency due to external factors other than human input. They are the safety players have to go in and fight without fear despite all the chaos. It is better, therefore, for undeads to be completely invulnerable to any path manipulation events except for unbreakable walls and ground, which are absolute and block anything. This means explosions won’t send skeletons flying away when the necromancer needs his soldiers to parry the attack of a Paladin.

My book recommendation this time is Emergence in Games by Penny Sweetser.

Contrast and Interest Curves

It doesn’t matter the stimulus, you’ll either get bored from or addicted to it, eventually. That’s the sad truth every designer has to face before learning how to minimize this effect.

It can be assumed that the reason behind saturation of stimuli is the necessity of energy conservation and the limits of attention: Animals must be aware of what’s important and new. The activities we already have a good grasp of shouldn’t be occupying space in our conscious attention, otherwise we would never really master anything, from walking to talking to driving to playing, and would end up overwhelmed by the amount of details that go into living a regular life. That’s also the reason why unexpected slips and recklessness emerge: driving at 80km/h will eventually make it easier to drive at 100… and so on.

Knowing that, how can we prevent players from getting bored? Just progressive difficulty suffices? What about new abilities? It is true that the previous two are very important for a good game and observed in most, but the essence behind them is what we are going to analyze: contrast and interest.

Further into this article, we’ll be making some very exaggerated graphs to show how players lose interest over time when exposed to the same stimuli too frequently. We are not specifically focusing on system rewards, though we do talk about them. The priorities here are the actions of players and responses from the game, such as space-time simulation and visual / sound effects (aesthetical rewards).

In my currently nameless top down hack n’ slash shooter (?), your main action is attacking: you “shoot” undead-bullets (skeletons with swords) that dash forward and slash away at paladins.

It is then possible to move the undead-bullet from one point to another for it to block enemy attacks as it moves across. Players will be doing both of those actions most of the time.

Having two core mechanics will make them balance and refresh one another, especially when the player has to interchange their use.

Outside of them, you can (and should, if possible) add more mechanics to make the interest curve take even longer to start going down. Put system rewards in the middle (e.g: experience points), unexpected or predictable power spikes (crits and ultimate abilities) and anything else that makes sense to be there, but obviously minding your intended experience. In our case, for example, we are using Block Utilities and Demons.

Block Utilities are craftable runes that players can take to battle. With them equipped, blocks have a chance of granting special effects such as healing, burst of attack speed and others. Like critical strikes, but not really.

Then, there are Demons. Any paladin you kill grants one or more souls, depending on the strength of its class. Having enough souls allows you to summon a powerful creature of independent behavior that moves around destroying every paladin it sees. We have many interest curve enhancers on this one: First, the earning of souls, which is a good reward (systemic and aesthetical) to show progression. The second one is the summon itself. The other sources of interest come from the amount of times the Demon performs badass abilities that add chaos to the battlefield.

Kills increase interest by quite a bit because it shows meaningful progress spikes.

It doesn’t stop there: Like previously mentioned, the addition of new patterns to both abilities and challenges will keep this cycle fresh for as long as the game lasts.

One of the special things about intertwined interest curves is that all those mechanics playing around within the same world space-time end up creating unexpected situations that increase interest even more than what was predicted.

My book recommendation this time is A Theory of Fun for Game Design.