Unity Engine games developed with SpatialOS' cloud-based multiplayer Game Development Kit (GDK) are now in violation of Unity's terms of service, according to SpatialOS maker Improbable. The decision imperils the operation of many in-development game projects, including some that have already been released to the public.
Since its open beta release in 2017 (in partnership with Google), SpatialOS has allowed developers to easily integrate mass-scale multiplayer into their games by running a persistent version of the game in the cloud. But Improbable now says that a recent change in Unity's terms of service means the SpatialOS is essentially blocked from working with the Unity Engine.
The newly updated clause 2.4 of the Terms of Service now specifically excludes "managed service[s] running on cloud infrastructure" which "install or execute the Unity Runtime on the cloud or a remote server." Though the terms of service were changed on December 5, Improbable says Unity confirmed directly to them this week that the update "specifically disallow[s] services like Improbable’s to function with their engine. This was previously freely possible in their terms, as with other major engines."
As a result, Improbable says, "this change effectively makes it a breach of terms to operate or create SpatialOS games using Unity, including in development and production games." That list of imperiled games includes Bossa Studios MMO World Adrift, VR MMO MetaWorld, upcoming 1,000-player battle royale title Maverick: Proving Grounds, and Klang Games' upcoming MMO Seed, among others.
Improbable says the ToS change comes as the company was actively negotiating with Unity "to find a way to do more together." Improbable also says it is continuing to talk to Unity in an effort to reverse the decision, though its license to work with the Engine has currently been revoked. A Unity representative was not immediately available to respond to a request for comment.
"Overnight, this is an action by Unity that has immediately done harm to projects across the industry, including those of extremely vulnerable or small-scale developers and damaged major projects in development over many years," Improbable says. "Games that have been funded based on the promise of SpatialOS to deliver next-generation multiplayer are now endangered due to their choice of game engine. Live games are now in legal limbo."
Improbable is promising to "do everything in our power to help developers using SpatialOS with Unity to finish, release and operate their games," including using an emergency fund to help with developers' finances, releasing the Unity GDK as an open source project, and assisting in porting to new engines as a last resort.
"SpatialOS [has made] it easier [for me] to build large-scale multiplayer games using a cloud-based solution," developer AtomiCal writes on the Unity forums. "Today I woke up to a message essentially pulling the rug from under my feet saying that I can't do that anymore. Unity won't let it happen."
We'll update this story as we hear back from Unity and any other developers affected by this decision.