"There is one fundamental choice you must face when you start to make an asymmetrical game like ours: Either make both sides feel similar with only minor differences, or make two completely different games," says Ashley Pannell, creative director of Behaviour Interactive."Both solutions bring their own unique challenges in terms of fun and balance."

Behaviour Interactive's Dead By Daylight  offers two games in one: one in which a killer (inspired by slasher movies) stalks a handful of victims, and another where several valiant team members try to complete objectives and stay together without meeting a gruesome end.

"We decided to embrace the asymmetry as much as possible," says Pannell. "We knew we would be constructing two very different experiences that would appeal to two different types of players."

It's a tense game that creates a unique tension, and according to SteamSpy, it has garnered over 800,000 sales in the two months since its release. It also creates many unique problems and challenges for the developers as they try to refine the experience. "With humans controlling both sides, it makes for tremendously interesting gameplay that is very emergent." says Pannell. "Of course, this brings challenges for the balance, but it makes for something quite different from what you have played before." 

Hide and Seek

Dead By Daylight is indebted to another classic asymmetric multiplayer game. "The initial prototypes focused on the simplicity of hide and seek." says Pannell.

Most slasher/horror films devolve into this at some point. With the all-powerful villain stalking the potential victims, they have to hide to stay out of sight. Getting caught often means a gruesome death, and it was this simple framework that would slowly evolve to become Dead By Daylight. "Being afraid, or at the very least stressed, makes the game tick along." says Pannell.

"We tried to take as many tropes as we could from movies we loved, while being careful to stay open to new ideas," says Pannell. "It was clear to us that we should support the whole range of horror and make sure that we could feature many different types of killers and fold them into our own fiction. We didn’t want to limit the gameplay with just one set of tropes."

The various types of killers found in horror films--the hunter who uses traps, or wraith who can silently stalk their victim--gave the developers ideas. " We went back to what used to scare us as children." says Pannell.

It would prove to be a challenge to make certain horror villains work within a gameplay setting. The survivors would have to be balanced and rebalanced in order to make play against these increasingly challenging villains fair. It’s difficult to just take what is found in movies and replicate it for a game. Good horror films are working on a different psychological level, manipulating the viewer using tried and tested techniques." says Pannell.

The Arms Race

This is a game where one player controlling the slasher will be fighting against four normal human opponents, each with their own strategies and ideas to add to the group. "One of the hardest parts is trying to make each side feel fun without weakening them too much." says Pannell. "Seeing as every killer has a unique power, this was a considerable challenge." 

Each of the game's playable killers has their own unique moveset making different gameplay demands from the four potential victims. "Balancing involves slowly empowering each side with features--a process that came to be known as 'the arms race.' We would introduce a new mechanic and then work to level the playing field before beginning the process again,"  says Pannell. "It is a process that we are still actively following even after release as we react to the new and emergent ways people are playing the game."

Balance Through Randomness

There's nothing worse than a horror movie villain that isn't scary. Balancing abilities would go a long way to making the game feel fair, but the killer is still stalking the game world for four living, moving targets. That's a lot of ground to cover, even with special abilities, and if the players knew a given map well, they'd easily be able to plot the best route to beat a given area. To combat this, and to add a little horror spice, Behaviour Interactive added some procedural elements to the game's maps. 

"There were three key pillars to the game that we tried to adhere to throughout development," says Pannell. "You never know where you’ll be, you’ll never know what you’ll face and you never know where your objectives are."

The procedural elements meant that players have to explore and learn to work together as a team, all with that omnipresent, fearful knowledge that something is stalking them. This also sets both teams on the hunt as the game begins, again providing much-needed balance to play, while also creating a little fear and tension.

"The goal of going procedural was based on the nature of what makes us scared. One of the key factors behind fear is that once it is repeated, you start to lose the fear almost immediately." says Pannell. "This runs against the way many multiplayer games function, where mastering the layout of levels is a key part of the game. We want players to have to learn to adjust to their surroundings on the fly, allowing natural human errors to manifest themselves under stress."

The nuances of each match come down to where everything is, and how players collide with one another,"  says Pannell. "The whole experience is about players adjusting to situations as they present themselves. We leave the core game mechanics on a very high level, and then allow situations to drive the moment-to-moment gameplay."

And where multiple players are involved, those moment-to-moment gameplay experiences will always be varied. "One of the fun parts of the game is that no matter how good your plan is at the start, you will have to adjust as the game will very rarely go the way that you planned it to," says Pannell.

In addition to slashers, the team of normal humans have to worry about backstabbing. "Obviously, having friends around brings a feeling of security, but the systems in the game are designed to let players’ natural playstyles come out," says Pannell. "It’s rare that all your friends are as altruistic as you are. There is always one who wants the points more than others, right?"