What is the ultimate dream of a live-service game? Before generating massive revenue or gathering tens of millions of players, there is a goal that must be achieved first: simply surviving.

Behaviour Interactive's 'Dead by Daylight' celebrated its 10th anniversary last June. Starting as a small asymmetrical multiplayer horror game in 2016, it grew into Behaviour's flagship long-term live-service game through numerous updates, platform expansions, and collaborations with famous horror IPs.

However, it was not a game built with a 10-year vision from the start.

"We had no 10-year plan whatsoever. To be honest, we didn't even have a plan for next Tuesday."

At gamescom dev held in Cologne, Germany on the 26th, Behaviour Interactive Senior Product Director Rose Li and Senior Programming Technical Director Remi Veilleux reflected on the past decade under the topic "Feeding the Beast: Keeping a Live Service Game Alive and Thriving for a Decade." What the two emphasized was not building a perfect game from the start to last 10 years, but making the choices needed right now and being able to reverse past decisions as the game grows.

Build for the Game You Have Today, Not the Game 10 Years from Now

When it launched in 2016, 'Dead by Daylight' was a much smaller game than it is today. The development team's resources were limited, and they expected their main player base to stay within North America. Building servers around the world was not a realistic option.

Therefore, in the early days, they opted for a Listen Server model where the Killer player's PC directly hosted the match. Because Survivors connected to the Killer's PC, it suffered from issues like host advantage and varying experiences based on network conditions, but it carried the clear advantage of incurring no global server operating costs. Above all, it was the choice that allowed a small development team to actually launch the game.

"We couldn't build infrastructure for the game we dreamed of becoming 10 years down the line. We built what was needed for the game back then with the resources we had at the time."

As the game became successful, the situation changed quickly. Four months after launch, Michael Myers from 'Halloween' joined the game, and subsequent collaborations with numerous horror IPs became a core part of 'Dead by Daylight's identity. In 2017, the game expanded platforms to PlayStation and Xbox.

In particular, a crucial change occurred during the transition to consoles: building an in-house backend to move player progression and save data, which had been stored locally, to the cloud. At the time, it was simply work done to make the game function properly on consoles, but the foundation built back then later served as the basis for implementing crossplay and cross-progression.

The first principle emphasized by the two developers here was simple: "Ship the game you have today, not the game you dream of having in the future."

There is no need to find a solution that will last forever right from the start. If a choice can take the current game to the next step, that is enough. However, once you actually arrive at that next step, you must be prepared to move on to a better choice.

Technology That Was Once the Right Answer Eventually Becomes a Problem

The Listen Server model that enabled 'Dead by Daylight' to launch in 2016 began to hold the game back as it grew. Issues such as host advantage for Killers, security vulnerabilities, and cheating worsened, eventually leading Behaviour to decide on introducing dedicated servers.

However, changing the network architecture of a game already in live service was no simple task. The migration took nearly two years. They had to fundamentally redesign how match interactions were processed, and because latency could not be entirely eliminated, numerous compromises had to be made between responsiveness and fairness.

While dedicated servers did not solve every problem, they greatly expanded the development team's scope of control over the game. They reduced host advantage, strengthened security and anti-cheat measures, and by offloading certain calculations to the server, eased the burden on players' devices. Above all, it laid the groundwork to later implement crossplay, connecting players from different platforms in a single match.

"Sometimes, to keep a live service game alive, you have to accept that what got you here won't get you where you need to go next."

The transition to Unreal Engine 5 in 2024 was a similar choice. They had to replace the underlying engine while maintaining hundreds of perks, abilities, and systems accumulated over eight years—all while releasing a new chapter every quarter. The development team used this as an opportunity to clean up legacy tech at the same time.

Veilleux described this process as "modernizing an airplane inside and out without landing it." Although it required taking on a massive technical burden in the short term, it was a necessary investment to respond to new hardware and features and keep evolving the game going forward.

Breaking the '1v4' Rule Kept for 8 Years

Technology was not the only thing that required abandoning legacy assumptions. In 2024, Behaviour touched one of the oldest rules in 'Dead by Daylight'.

One Killer and four Survivors.

Breaking the '1v4' format that had been the foundation of the game for eight years, they created a '2v8' mode where two Killers face eight Survivors. It was a simple idea to let Killer players queue up with friends, but technically, it meant redesigning a structure that the entire game had assumed for eight years.

The result was a success. 2v8 immediately received a record response, reassuring the dev team that old assumptions were worth reconsidering. Conversely, unexpected new problems arose as Killer players flooded in to play 2v8, causing matchmaking queue times to surge.

To solve this, they created 'Play While You Wait.' This feature allows players to play a separate match as a Survivor while maintaining their place in queue as a Killer. According to the dev team, this reduced perceived wait times by approximately 80% in 2v8 and around 70% in the existing 1v4. Of course, it was not a fundamental fix, as actual wait times did not vanish for players who exclusively wanted to play Killer.

What started as an experiment, 2v8 has now become a recurring mode. While adding new modes creates another issue by fragmenting the player base across multiple matchmaking pools, the development team continues to repeat the process of releasing content, assessing player response, and making adjustments.

The way the two summarized this approach was 'Dream, Reality, Result, Repeat': dream, face reality, deliver results, and repeat.

And this was how 'Dead by Daylight' survived for 10 years. Technology that was the right answer in 2016 became a problem to solve a few years later, and even the 1v4 rule, once considered the game's core identity, was revisited when necessary.

"Surviving for a long time doesn't always mean sticking to what used to work. Sometimes, it comes down to knowing when to rethink those decisions."

There was no 10-year plan from the beginning. Instead, they made necessary choices at each moment and changed them when those choices no longer fit. A live service game that lasts 10 years is not one that foresaw a decade ahead, but one that remained adaptable over 10 years.