Localising Kingdom Come: Deliverance II for the Japanese Market

Medieval Bohemia runs on feudal hierarchies, Christian customs, and social codes that don't translate cleanly to East Asian cultures. 

At 2.2 million words, Kingdom Come: Deliverance II (KCD2) is one of the largest recorded game scripts in history, surpassing the previous record set by Baldur’s Gate III. 

Warhorse Studios, PLAION, and Deep Silver partnered with Side to bring that world to Japanese players, with our Side Tokyo studio delivering Text Localisation, Localisation Quality Assurance (LQA), and full Japanese Voice Production. 

What followed was 18 months of work across text, voice, and LQA: the challenge of making a culturally distant world feel local. 

The Challenge: Nothing Translates Directly 

Localisation that feels off – unnatural dialogue, inconsistent tone, culturally tone-deaf adaptation – gets noticed. And talked about.  

That made KCD2 a particular challenge. Japanese required full Audio Localisation alongside text translation and LQA, adding another layer of complexity to one of the largest localisation projects in game development. 

The setting itself also presented an obstacle. Feudal titles, religious authority, and social rank, along with every interaction in KCD2, rest on assumptions that don't carry over. Every choice had to be researched, reasoned, and made consistently across a cast of hundreds of characters. 

What’s more, the script was enormous – and unlike many games, it wasn't recorded in just one language. KCD2 was recorded in six: initially written in Czech, then localised into English and finally into the various other languages.  

While most of the other localised languages were Indo-European, Japanese was unique in being the only East Asian language to be fully localised. The Japanese VO alone accounted for 266,218 lines of dialogue, 2,037 hours of recording, and 5,260 hours of script rewriting.  

And the script never stopped moving. Text updates and voice recording ran in parallel throughout production, meaning that the team was constantly translating, adapting, and recording content as it was being revised.  

The Approach: Owning Production 

Early scope visibility changed everything. With KCD2's scope in hand before production, Side built the foundation for the Japanese localisation strategy up front. Character documentation, shared linguistic resources, and decision frameworks gave every translator and voice director the same reference point.  

Coordinating it all was a dedicated programme management layer on our side. With producers managing parallel workflows and batch deliveries, text translation, LQA testing, and audio could move at once without losing coordination. 

The adaptation itself was research-driven by our team, balancing historical authenticity with readability. Medieval Bohemian concepts had to land for a modern Japanese audience without losing the weight of their setting – accurate enough to hold up and clear enough to play. 

The team integrated directly into Warhorse Studios’ pipeline, using their proprietary systems and Perforce for version control. Rather than waiting on client-driven content batches, Side Tokyo managed scheduling by monitoring updates and deciding what got recorded and when. With text and audio moving simultaneously for 18 months, that ownership was critical. 

LQA also ran alongside production throughout as a continuous quality layer built into the process from the start. 

The Result: It Landed 

Delivering KCD2's Japanese audio meant recording at 150 lines per hour for non-cutscene content – one of the fastest paces Side Tokyo has worked at. Across 18 months, that pace held without the script ever sitting still. 

Kingdom Come: Deliverance II launched in February 2025 to a 95% critic recommendation rate on OpenCritic, with critics singling out its voice acting and polish. It went on to surpass 6 million copies sold worldwide. 

In Japan, the localisation held up to scrutiny. Players praised the game's immersion – the sense of living in the Middle Ages – with local media praising the quality of the Japanese localisation.  

That positive reception was echoed by the team at PLAION, who highlighted Side's professionalism and the quality of our Japanese audio and localisation efforts throughout the project: 

Localisation That Carries a World Across 

Kingdom Come: Deliverance II makes the case: cultural distance isn't a barrier. With the right groundwork, a world built on 15th-century Bohemia can feel just as real to a player in Tokyo as one in Prague. 

That's what localisation is supposed to do – not move words from one language to another, but carry a world across. 

If you're bringing your game to Japan, or any market that asks for more than just translation, get in touch with Side and let’s see what we can build together.