The Like a Dragon series (formerly known as Yakuza) has been built on developer Ryu Ga Gotoku Studio’ internal engines for as long as anyone can remember, with the Dragon Engine having served as its primary development toolset since being introduced in Yakuza 6: The Song of Life. Last year’s Like a Dragon: Ishin! broke series convention by being built on Unreal Engine 4, but it doesn’t look like that’s indicative of the series’ future in any meaningful way.
Speaking in a recent interview with Japanese outlet Type, Ryu Ga Gotoku Studio technical director Yutaka Ita touched on the aforementioned topic, saying that development of Like a Dragon games should ideally always be on the Dragon Engine (or some other internal toolset), owing to ease of use, and the fact that the toolset was designed specifically to suit the needs of the series.
“In order to develop Like a Dragon, the Dragon Engine is something that must never be lost, and we will continue to develop an in-house engine,” Ita said. “Dragon Engine concentrates its development resources on the functions necessary for Like a Dragon, and above all, the speed at which new functions are added is a big advantage. If you’re using a general-purpose engine, you can email support and get a reply in about 3 days, but if you ask the programmer next to you, it only takes 5 seconds. I think this difference is significant.
“But it’s not a good idea to think, ‘Our game engine is the best!’ In particular, I believe that we programmers should always have a sense of urgency that ‘that one is greater, and we need to work harder.'”
So why exactly has Ryu Ga Gotoku Studio been dabbling with external, third-party engines like Unreal Engine and Unity of late, like the former being used in Like a Dragon: Ishin! last year? According to Ita, that was down to the studio want to expand its familiarity with multiple engines rather than becoming too reliant on a single one, as well as the potential ways that could improve the Dragon Engine as well.
“We made this choice because we have to adapt to changes in the gaming industry,” Ita explained. “Perhaps, in the future, if a very good general-purpose game engine comes out, all the game companies in the world will use it.
“At that time, if Ryu Ga Gotoku Studio was in a state where only the Dragon Engine could be used, it might not be able to compete in this world anymore. We don’t know which direction the game industry and development environment will take in the future. That’s why in the training for new employees at Ryu Ga Gotoku Studio, they learn how to make games using three engines- Unreal Engine and Unity, in addition to the Dragon Engine.
“Knowing the other two engines will help us make the Dragon Engine better, and we’ll be able to keep up with it whenever the direction of the gaming industry changes. That’s what trilingual education is for.”
For instance, Ita explained that the visual and lighting improvements enabled by Unreal Engine in Like a Dragon: Ishin! prompted the studio to implement similar improvements in Dragon Engine for Like a Dragon: Infinite Wealth.
“We began to see what we had been lacking until now,” he said. “One of those things is the expression of light. Because we used Unreal Engine for Like a Dragon: Ishin!, we were able to create a very beautiful expression of gloss in a bright daytime environment and a high level of depth of field.
“On the other hand, Like a Dragon: Infinite Wealth was developed with the Dragon Engine, but after receiving a request to incorporate the expressions that we were able to achieve in Ishin! into Infinite Wealth, we added new lighting features to the Dragon Engine.”
