Three to four hours. That is the time a popular GitHub guide says it takes to merge two video games — Elden Ring and Spider-Man, in its example — using a Claude-based AI agent to write the code, as Decrypt reports. The guide warns first results are rough around the edges, but the workflow needs no programming from the user: describe what you want, test the output, give feedback, repeat. The agent does the coding.
The mechanism behind the mashups is a ‘passthrough mod.’ Both games run simultaneously; one hosts the world and the other supplies the gameplay — movement and combat. So you are not importing Elden Ring’s boss Malenia into a Minecraft world; you are running Elden Ring’s combat logic on top of Minecraft’s world, or vice versa, with the two processes stitched together. That is also why these mods can be built in hours rather than the months a conventional total conversion would take: no assets are recreated, both executables are already on the machine.
The mods, by the numbers
The most viral example is Minecraft in Elden Ring. The mod exposes 1,600 Minecraft items inside FromSoftware’s game, including functioning redstone contraptions, creative mode, Ender Pearl teleports and spawn eggs — so a player can summon creepers to fight Malenia. It also layers in Black Ops guns, letting the player switch between Minecraft and Call of Duty arsenals mid-fight. Its creator, Toby Jacobs, has not released it publicly; he says he is open to the idea but would first have to port it to Windows, having developed it on a Mac.
One of the earliest mashups to spread put Skate’s skateboarding into Call of Duty: Modern Warfare 2 maps. “Imagine hitting a trick shot with this. We will see clips soon, any moment now,” one X user posted; another called it “the greatest thing that will ever happen in Call of Duty.” A third mod reversed the formula, dropping Modern Warfare 2 weapons — including the Intervention sniper rifle — into Minecraft, where the player hit a 25-kill streak on villagers and called in a tactical nuke.
Then there is Marvel’s Spider-Man swinging through Batman’s Gotham City — two competing publishers’ flagship properties in one frame. “Marvel and DC are friends now,” one X user posted. “Wait ’til I get a DMCA,” the mod creator replied. Rounding out the list: Mario Kart vehicles in Call of Duty: World at War’s Zombies mode, with players tripping zombies on bananas and running them over for kills. “[We got] Mario Kart in World at War Zombies before GTA 6,” one user joked.
Reactions on social media have run to “one of the coolest things I’ve seen in gaming in 10+ years” and talk of “the renaissance of gaming.” The harder question is distribution, and here the record is thin. Every example named involves assets from at least two rights holders running in one process; a Mac-only build that even its creator has declined to release is the current state of the art. The next number to watch is whether any of these mods actually ships — Jacobs’s Windows port being the leading candidate — and what the rights holders’ lawyers say when they see the videos.