A Minecraft world could automatically beat itself – that is, kill the Ender Dragon and trigger the end scene credits – after roughly 2 billion years, according to a fascinating new experiment about the most popular survival game of all time.
For quite a while, it's technically been possible for Minecraft to play itself. To beat the game, you just have to go to The End and kill the Ender Dragon, typically by showering it with arrows after first destroying the crystals around The End that regenerate the dragon's health.
Even without a player's input, Minecraft mobs can do all of this, but with one big caveat. For this to work, the Minecraft world itself must come with an active portal to The End, as mobs can't create Eyes of Ender or place them in the portal frame to activate it. But with a 12-eye portal open by default, it's theoretically possible for random Minecraft mob behavior to kill the Ender Dragon.
YouTuber RedLogic wanted to find out how long it would take for this theory to play out. "Since this would take an impossible amount of time to happen in real Minecraft, I had to speed up the universe itself," his video description explains. "So I simulated billions of years, tracked the rarest chain reactions, and searched for the timeline where Minecraft finally beats itself."
Without billions of years and limitless hardware available, RedLogic used a Monte Carlo simulation to predict the events of a Minecraft world that spawned with a 12-eye End Portal. The video chronicling this sim is a visualization of what would happen in a real game world that actually ran for this long (specifically, in world seed -535646876083114041).
Monte Carlo sims essentially use samples of random variables to model uncertain outcomes. Through the law of large numbers – which states that with enough samples, your discovered mean approaches the true mean of an experiment – they can reasonably estimate average results through many, many models. IBM has a good, short video on the subject.
You can't run Minecraft for 2 billion years, nor can you perfectly simulate every single game action on that scale, but you can compress Minecraft mob behavior into random variables and plug them into a simulation to compute an average. This is about what RedLogic did.
This experiment hinges on an Enderman placing pumpkin blocks on snow to create Snow Golems. This is why you want that 12-eye portal to be in a snowy biome. Those golems must then move underground near the activated End Portal to aggro and detonate Creepers to destroy blocks and open a path to the portal.
From there, the Enderman must go through the portal and place blocks inside The End – with a path to the surface opened by more Creepers – to build paths for more Snow Golems. The golems in The End would fire snow at the wandering Enderman and occasionally destroy the Ender Dragon's crystals in the process. Once all the crystals are destroyed, Creepers have to go into The End and, right as the Ender Dragon flies close by, be detonated by Snow Golems to damage the dragon.
By calculating the odds of different mob behavior – for example, an Enderman moving from point A to point B, picking up a pumpkin, or moving into the Portal – you can simplify the number of variables. "Rather than calculating millions of tiny, random decisions one by one, the simulator samples how long it takes until one of those meaningful events happen," RedLogic explains in the video.
The guts of the sim are behind RedLogic's Patreon account and therefore unclear to me, but the gist is this: Minecraft mob behavior makes up our independent variables, and we can use them to chart probabilistic paths toward dependent variables like the Ender Dragon flying into a Snow Golem right as a Creeper explodes nearby. We don't have to simulate every last golem; we just need to know how the dragon, your average golem, and your average Creeper behave.
You're making sense of the infinity of time with Monte Carlo sims. Finding "the timeline where Minecraft finally beats itself" is a good way of putting it. The scale of the experiment is staggering: some 1.975 billion simulated years in, the dragon finally falls. Somewhere, Minecraft's end credits reflect off the dewy bones of a skeleton in a gamer chair.
Here are a few illustrative numbers and quotes from RedLogic:
- "The same golem wandered The End for 18 million years" after destroying one crystal before destroying another
- "After almost a quarter of a billion years, the dragon had just lost 2% of its health"
- 34,777 simulated years into the experiment, a pumpkin was transported for another 2,000 years before becoming the first Snow Golem to carve a path toward the portal
- It took 2.9 million years for a route out of the End-side portal room to open
