RENNSPORT Uses rFactor2 Code?
Image credit: RENNSPORT

RENNSPORT Allegations: ISI-Licensed Code Used As Baseline

RennsportrFactor 2

In a post on the Studio 397 forum titled “Rennsport (Game) use physic construction from rFactor2”, user haunetal1990 points out several examples in the code of RENNSPORT which also exist in rFactor2. This puts RENNSPORT in the spotlight, as its developers have repeatedly claimed to build everything from scratch. Moreover, the question arises on what basis the RENNSPORT developers actually are using the code.

Last updated: October 5, 8.30 am CEST

Of course, “in dubio pro reo” applies here as well, and we will definitely not make any rash conclusions, let alone allegations. So before we get to the burning questions, let us first clarify what we are talking about. Here are the crucial facts in chonological order.

Confusion About License

RENNSPORT is a racing simulator video game for PC in development by Competition Company GmbH, based in Munich, Germany. rFactor 2 is a racing simulation for PC from Studio 397, a subsidiary of Motorsports Games (MSG) since April 2021. It was originally created by Image Space Incorporated (ISI) as the successor to the original rFactor.

According to our research, ISI issued a license for rFactor2 code to RENNSPORT in 2021 – however, without telling Studio 397 or (later) Motorsport Games, who now own rF2 and S397. But was ISI even authorized to issue rFactor2 code licenses at that point?

The studio entered a partnership with Dutch software company Luminis, which resulted in the development of rFactor2 being handed over to Studio 397. Following this, Studio 397 added several new features and content to the simulation.

Using someone else’s program code is a copyright violation and can be legally prosecuted. The RENNSPORT developers have repeatedly stated to have been “starting from scratch” with their physics. The recent revelations now cast this claim in a different light.

RENNSPORT Uses rFactor2 Code

The similarities in the code of RENNSPORT and rFactor2 are indeed too striking to be a coincidence. User haunetal1990 has provided several examples.

Code of the RENNSPORT physics data files:
rFactor2 code from the old HDV file:

RENNSPORT Uses rFactor2 Code?
As user haunetal1990 found, RENNSPORT uses code from rFactor 2. Image Credit: haunetal1990 / Forum Studio 397

Another example:
RENNSPORT: TurnsLockToLock=0.666667;SteeringFraction=0.364299
rFactor2: TurnsLockToLock=0.666667;SteeringFraction=0.6

As user Kahel subsequently points out further down in the aforementioned forum thread, “you can have similarities […] here and there… but Entire Exact same line of code (and structure) is statistically (almost) impossible…

Motorsport Games: No License to RENNSPORT

Hence, we can consider it as a fact that there is rFactor2 code in RENNSPORT. But how did it get there? Did they take it without permission? Or did they (lawfully) acquire a license? And if so, why have they not stated this?

According to MSG and Studio 397 in their X post, “Motorsport Games has not issued a license for rFactor2 game technology to any developer at this time nor are [they] aware of licenses issued by Studio 397.” However, apparently RENNSPORT also uses code values identical with rFactor2 values in DLC/encrypted content, i.e. code which was developed by Studio 397 and MSG. How did that get into RENNSPORT?


Hours after the MSG statement, RENNSPORT CEO Morris Hebecker released a statement of his own. According to this, “all content and libraries used for the production of RENNSPORT are created by us, commissioned, or licensed appropriately:” Furthermore, Hebecker points out that “our current technical direction is to first improve what we can with state-of-the-art technology and if we find fundamental limitations, we rewrite it.

In a longer post on the RENNSPORT website, Hebecker adds that “there are also cases where we have intentionally chosen compatibility and thus will have some code that resembles other software.” As an example, he mentions that RENNSPORT supported exporting MoTeC Telemetry.

While this does not answer any of the questions above, it is not denying the existence of the rFactor2 code in the sim either. However, it does imply that RENNSPORT feels like it has the code properly licensed.

While this does not answer any of the questions that came up initially, more light was shed on the situation about 24 hours later.

ISI Code As Baseline

As October 4 drew to a close, RENNSPORT offered an explanation into the matter on their website. During development, it had turned to ISI, “to fully acquire a license to use their physics processing system (known as “ISI Technology”) to act as that baseline.” This explains the parallels in code found within RENNSPORT files.

However, these parts are not set to remain in place, as the update states. Instead, “our ambition is still to create custom physics. Such an undertaking from scratch is a multi-year endeavour. A full rewrite will enable us to support more advanced racing experiences, such as implementing mixed weather systems, larger races and higher quality physics by increasing the physics thread frequency.”

Again, this implies that RENNSPORT is not only certain to have the parts of the physics engine licensed properly (via ISI, in this case), but also that it is not intended to be part of the full release of the title. Remember, RENNSPORT is still in a Closed Beta state.

Has “Code Hunting” Become A Common Method?

Is “Code Hunting” a common (exploit) practice in the virtual racing scene nowadays? This at least is what an anonymous user in the same Studio 397 forum thread states. This user claims to have worked with one of the esports teams who race on RENNSPORT and that they “regularly go hunting in code for games to look for any competitive advantage.” He calls it “scummy” but also says there was no real alternative as the “opposition” did it as well. Moreover, he claims that it was a known fact at recent LAN events that RENNSPORT used “chunks of code from rFactor2.”

RENNSPORT Uses rFactor2 Code? Anon User states that "Code Hunting" is common in esports
An anonymous user on the Studio 397 forum claims that “code hunting” is a common method nowadays.

What do you think of the situation? Tell us on Twitter at @OverTake_gg or in the comments down below!

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Cars, motorsports and racing games addict since 1974, I am constantly hunting for perfect authenticity and deepest immersion from the safety of my sim rig.