Improbable teams up with Epic after Unity revokes SpatialOS licence


The developer community has been thrown into chaos after Unity changed its Terms of Service to render all games made with Improbable’s SpatialOS in breach of Unity’s licence, before Epic Games stepped in to announce it would partner with Improbable to create an open integration between SpatialOS and the Unreal Engine.

The drama began with Improbable revealing that SpatialOS, its popular cloud-based development engine, had effectively had its licence to operate with games made in Unity revoked after changes to Unity’s Terms of Service made on December 4, 2018. Improbable said: “The game engine provider Unity recently changed (Dec 5) and then clarified directly to us (9 Jan) their terms of service to specifically disallow services like Improbable’s to function with their engine. This was previously freely possible in their terms, as with other major engines.

“Unity has clarified to us that this change effectively makes it a breach of terms to operate or create SpatialOS games using Unity, including in development and production games. Worryingly, this change occurred during an open commercial negotiation with the company to find a way to do more together.”

That led to speculation that games developed in Unity that use SpatialOS would have to be taken out of operation. Spilt Milk Studios, for example, tweeted that its game Lazarus, in open alpha, would have its servers taken offline, but later announced that it would return to operation: “Until either the servers are forced down or we’re told to turn them off.” Bossa Studios took to Twitter to reassure customers that it would keep Worlds Adrift operational: “Rest assured you will be the first ones to know if this situation causes any disruption to your experience. For now, Worlds Adrift is operating as normal.”

Sensing an opportunity, Epic Games, whose Unreal Engine is a direct competitor to Unity, then jumped into the fray. In a blogpost, jointly signed by Epic CEO Tim Sweeney and Improbable CEO Herman Narula, the two companies announced a $25 million fund to help developers struggling due to the move from Unity: “To assist developers who are left in limbo by the new engine and service incompatibilities that were introduced today, Epic Games and Improbable are together establishing a US $25,000,000 combined fund to help developers transition to more open engines, services, and ecosystems.  This funding will come from a variety of sources including Unreal Dev Grants, Improbable developer assistance funds, and Epic Games store funding.”

The statement added: “Unreal Engine provides full C++ source code for everyone, and its license ( ensures it remains open to all game developers and middleware providers, and enables all to collaborate together through SDKs, services, and forks of the source code. Likewise, Improbable is developing a completely open Unreal integration for its online game development platform, SpatialOS.”

Currently, it remains unknown precisely how many games – either in operation or in development – are affected by the change to Unity’s Terms of Service, but the developer community has been gripped by widespread trepidation, if not panic. Those developers would do well to visit Epic’s Unreal Dev Grants webpage and anyone worried about the controversy impacting their gaming should keep an eye on Improbable’s blog.