Decima is a game engine developed primarily by Guerrilla Games, and improved upon by Kojima Productions. It is currently optimized solely for PlayStation 4 system software and will be used to run Death Stranding.
With Hideo Kojima's abrupt departure from Konami in late 2015, he was left without a game engine of his own, as Konami retained rights to his studios' Fox Engine. Guerrilla Games was one of the first studios he visited during his tech tour in search of a new game engine. As a gesture of goodwill, Guerrilla gifted Kojima with a box containing the source code of their then-unnamed in-house engine, with no contractual obligations attached.
What began as a friendly donation soon developed into an intense collaborative effort. Realizing the engine needed to be altered to accommodate the starkly different world of Death Stranding, Kojima had his team improve on its code base and send their updates to Guerrilla. This led to the installation of a Kojima satellite team at Guerrilla, to further facilitate collaboration in the advancement of the engine. As a result of this Dutch–Japanese development, the engine was coined "Decima", named after the Japanese island of Dejima – the location of a Dutch trading post in the 17th century – in homage to the Netherlands' long-standing trading ties with Japan.
At The Game Awards 2016, Kojima showcased Decima through a Death Stranding teaser trailer, which featured a logo entitled "Decima" at the end. On December 3, Kojima and Guerrilla Games director Hermen Hulst publicly announced the joint effort between their studios during a PSX 2016 panel discussion: "We have people from an entirely different background that have worked on a different set of projects adding to the code base and to the ideas and that we can share again with the entire team back in Amsterdam."
Decima houses frameworks for scripting artificial intelligence, creating dynamic physics, generating logics and a tool suite for developing entire game worlds. The engine additionally supports physically based rendering and volumetric entities, with significant changes implemented for its use in rendering the world of Death Stranding. Kojima Productions and Guerrilla Games' collaboration has lead to constant wide-ranging improvements being made to the engine and circulated between the two studios.
- Hermen Hulst also mentioned Decima, the Roman goddess of childbirth, as an influence on the engine's chosen name, due specifically to her relationship with creativity.