Multiplayer School of Witchcraft and Wizardry? Video game modding and its copyright implications

Video games and "modding" - two terms that go increasingly hand in hand. With the growing availability of tools for modifying gaming systems, modding is becoming not only more widespread, but also a very popular way to improve individual games by “fans” themselves. But where does copyright law stand on such activities?

PC video games can be technically modified in number of ways, from minor graphical modifications to a complete remake. Moreover, for basic modding of a video game (especially visual changes), it is often enough to know the basics of coding/graphics, or to have programs that allow modding - so-called "toolkits". 

Probably the most famous examples of successful video game mods are Counter-Strike and Defence of the Ancients (DOTA), which are currently among the most played esport games ever. In the first case, it is a modification of Half-Life, whereas DOTA was originally a modification of Warcraft III.

Another example is also a mod of the recently released Harry Potter game Hogwarts Legacy, which transforms this "single-player" game into a multiplayer game, which the original version[1] does not enable. Although the studio Warner Bros. Games has not yet commented on this mod (and many others), in its  End User License Agreement (EULA) prohibits any modifications of the game[2]. 

So, what position do video game modders actually have in practice? 

Modding in a legal context 

A "mod" generally means any program, tool or other software not produced and/or distributed by the original developer or publisher of a particular game that modifies the mechanics, visual or other content of the game.

From a legal perspective, a game mod usually constitutes a so-called derivative work, i.e., a new work that enjoys separate legal protection but at the same time contains a "copy" of protected aspects of earlier works. Its creation and subsequent public distribution without the express consent of the developers of the original game (e.g., the game studio) will therefore generally constitute an unlawful infringement of the developers' rights. Similarly, silence on the issue of modding in a video game’s Terms of Service/EULA cannot be considered as an implicit consent by the developer to modding. An example of this is the approach taken by Rockstar Games, which we describe below.

So, if the respective developers don't like the mod for whatever reason, they can protect their rights, with the most common scenario usually being a takedown request[3]. In the case of "undesirable" mods, a claim for damages and non-pecuniary loss[4], possibly for lost profits, may also arise[5].

Approaches of game studios

Game studios often welcome mods, either by explicitly providing for them in their EULAs or by informally tolerating them. The existence of mods usually means that a community of players has formed around the game, which can be actively worked with, or at least marketed.

The most open to mods are of course developers whose games are virtually dependent on mods, such as Cities:Skylines by Paradox Interactive. This building simulation was developed with the very idea that it would be adaptable to user modifications and linked to the Steam Workshop service. It should be noted, however, that the game's reliance on mods sometimes frustrates[6] even the players.

Another example of a "benevolent" approach is that of Bethesda, whose EULA for TES:Skyrim explicitly prohibits the creation of mods using software other than the mod creation toolkit provided on its website. The EULA for this toolkit also explicitly states clear restrictions on what mods can be created and how they can be used, such as that mods cannot be used commercially and that mods that disparage Bethesda or its products are prohibited. At the same time, it should be noted that Bethesda compensates modders for their "contributions" to the game through its Creation Club.

Other game studios adopt a selective strategy, or support mods only indirectly. An example of this approach is Rockstar Games, whose EULA prohibits modding, but in practice the studio generally welcoms mods, although it explicitly notes that it does not grant any license to modders and that the studio can ban any mod at any time.[7] In fact, this is how the parent company of Rockstar Games already "closed the door" on mods that graphically enhanced the older instalments of the Grand Theft Auto series in 2021, as the studio itself subsequently released remastered versions of the games under the name Grand Theft Auto: The Trilogy – The Definitive Edition.

Finally, of course, there are studios that actively defend their games against modding. Apart from the aforementioned Nintendo, Walt Disney, much to the disappointment of many in the Star Wars community, stopped development of the Apeiron total conversion mod for Star Wars: Knights of the Old Republic in 2018[8]. In this case too, it can be assumed that the decision was mainly due to the upcoming official remastered version of this game[9].

Practical insight

Although it is clear that in theory modding is always legally problematic in the absence of explicit consent from the game developers, in practice it tends to be in a grey area. It is safe to say that without the explicit consent of the developers, a game mod may only be released for as long as the developers/studio tolerate the mod. However, practical examples such as Counter-Strike show that a game mod can grow from a leisure project to a worldwide phenomenon, or even a lucrative investment. 

In the current legal context, it is advisable for game developers to address the issue of modding in detail in their EULAs , so that they can pursue their chosen strategy with regard to modders.

On the other hand, modders should always read the game’s EULA carefully before investing their time and resources, or even publishing a mod, and try to obtain the necessary permissions from the developers (if possible). Proof that this is no "mission impossible" is evidenced by the mod Skywind which aims to re-imagine The Elder Scrolls III: Morrowind into a more modern engine, and whose development has been approved by Bethesda, the studio behind the original version of the game. 

If you encounter the above issues in your business, please feel free to contact us - we know what steps must be taken and we are ready to consult with you at any time and help you find an effective solution.