Dota 2 has a complicated lineage, and because of that a jury will be tasked with reviewing Valve’s ownership of the online game. As first discovered by Ars Technica, a recent court case between Valve, Blizzard, Lilith Games, and uCool has brought Dota’s ownership into question.

Intellectual property law itself is a complicated topic, but something game developers are almost required to have a basic understanding of. This particular case is an interesting example of what can happen when the lines of ownership get blurred as an IP passes from company to company.

Lilith Games and uCool, who were both involved in a lawsuit-triangle with Blizzard involving Dota a few years back, each have created mobile games that Blizzard and Valve say infringe on the Dota copyright by using characters and lore from the Dota universe.

In response to those allegations, uCool now argues that Valve doesn’t actually own the material being infringed on to begin with.

This is where Dota’s unique origins come into play. The original Dota was created as a mod for Blizzard’s Warcraft 3. Valve later picked up the property, and a couple of the mod's creators, to create its game Dota 2. Valve had is own legal kerfuffle with Blizzard shortly after, but an out-of-court settlement between the two allowed Valve to retain the rights for standalone Dota games.

The argument now being brought up by uCool suggests that Valve's claim on the characters and lore of the original Dota are illegitimate thanks to a 2004 forum post from "Eul", one of the mod's creators, in which they said Dota was now an open source project.

"From this point forward, Dota is now open source," reads the post. "Whoever wishes to release a version of Dota may without my consent, I just ask for a nod in the credits to your map.”

While Judge Charles Breyer denied uCool’s motion for a summary dismissal, the claim was enough to prompt Beyer to allow the case to move forward to a jury. In a legal document describing that denial, Breyer also brought the question of if Blizzard’s original EULA would have interfered with Eul’s ability to pass ownership of Dota to Valve to begin with.

With these complications in mind, the case is now set to be heard by a jury who will ultimately decide if either of these factors delegitimizes Valve’s ownership of the intellectual property it is accusing uCool of infringing on.