Can an agent discover capital investment on its own?

Minecraft gave us a small, concrete version of the patient optimizer problem: one clear quantity to maximize, a long tree of prerequisites, and an open question about whether a learner will build infrastructure without being told to.

Thought experimentNot an adopted plan
Status

This is a considered design from our discussions, not a commitment to build it. No agent has been trained and no budget is set. Partway through designing it we deliberately stepped back from game-specific architecture to focus on general principles (see the open questions). We keep the testbed because it makes those principles concrete.

The question in one sentence

Can a sensory-driven agent independently discover the concept of capital investment, sacrificing present reward to build increasingly general capabilities because it predicts they'll compound future reward, without the designer specifying the intermediate abstractions?

Why diamonds and not the Ender Dragon

We started with the obvious goal: beat Minecraft on Hardcore and kill the Ender Dragon. But that's essentially a finite quest. A competent enough agent eventually learns one sequence that finishes it, and then the interesting question is over.

"Maximize diamonds over a long horizon" is different in kind. It creates a real investment problem. Mine ten diamonds now, or spend twenty hours building infrastructure that later produces thousands per hour? A shallow agent takes the ten. A capable long-horizon agent should, in principle, see that the second option is better. What that requires is open-ended and recursive: better tools, experience points, enchanting, automated farms, redstone, TNT-based mining, better machines, exploits nobody has found yet. Technical Minecraft players such as ilmango have shown how deep that rabbit hole goes. We're not asking an agent to copy their machines. They illustrate how much capacity a world can hold for those who discover it.

The rules

One external reward, diamonds held, and nothing else. No reward for iron, tools, crafting, the Nether, farms or machines. They matter only if the agent discovers that they raise expected future diamonds. The constraints we want to keep, whatever the implementation:

  1. No privileged knowledge of which actions are useful.
  2. No hand-written progression tree.
  3. No predefined pathfinding toward objectives.
  4. No predefined high-level skills.
  5. The environment still decides whether attempted actions succeed.
  6. Long-term value has to emerge from experience.

We also ruled out a class of solution. Systems like Voyager, where a language model writes code against a game API, are impressive, but they import human knowledge wholesale. We wanted perception to drive action move by move, without scripted navigation tools like Baritone. That exclusion applies to this benchmark. It isn't a claim that language models have no place anywhere in this research.

We're comfortable abstracting motor busywork. An agent can target a block and issue "break" rather than emit thousands of identical clicks, or craft without dragging items around an inventory screen. It still has to work out when, where and why to use each action. Abstracting which actions are useful would be a real concession. Abstracting finger movements isn't.

A subtle design choice: when does the game end?

If reward is diamonds held at a known final time, a capable agent can just compute "invest for 91 hours, mine for 9." That's a scheduling problem, not open-ended investment. Making the end probabilistic (each step has a small chance of being the last) forces a continual trade-off between exploiting existing capacity and building more. We think that's the more honest version of the problem, though it's still a design choice rather than a settled one.

Removing scaffolding gradually

Rather than starting with the full open-ended task, scaffolding comes off in stages. The same architecture and learning process are used throughout. The curriculum is in where the agent starts, not in hand-coded behaviour.

PhaseStarting conditionsGoal
0Iron pickaxe, undergroundOne diamond
1Iron and a crafting tableOne diamond
2Stone toolsOne diamond
3NothingOne diamond
4NothingMaximize diamonds over 2 hours
5NothingMaximize diamonds over 20 hours

The point of the later phases isn't whether the agent succeeds but where it breaks. Ablations (adding memory, temporal abstraction, learned skills, autonomous subgoals, a diverse population) would show which ingredients actually carry the weight.

What to measure

Final diamond count is the least interesting number. Better ones:

How it's likely to fail

What exists today

Literature Our best reading of the current state, which we're always ready to have corrected:

CapabilityStatus
Learn Minecraft from pixelsYes
Reach a diamond from sparse-ish reward without demonstrationsYes, with DreamerV3, but using 12 milestone rewards
Behavioural priors from unlabelled videoYes, with VPT, though it inherits human strategy
General open-world benchmarkYes, with MineDojo
Discover diverse primitive skills without rewardIn simpler domains (CIC)
Escape deceptive sparse-reward explorationPartially (Go-Explore and similar)
Self-chosen latent subgoalsIn much simpler tasks (Director)
Open-ended co-evolving curriculaIn much simpler environments (POET)
Hour-scale abstractions from raw actionsLargely unsolved
Continual skill accumulation without forgettingLimited
Inventing sophisticated technology end to endNo convincing demonstration
Building capacity because of a very distant reward, at this scaleNo

In short, the pieces exist and the integration doesn't.

The first milestone that would matter

Not a world-eating TNT machine. Something far smaller, which we think would be a genuine result:

Will an agent reliably, even once, voluntarily spend time and resources on something that temporarily reduces diamond collection, because its learned model predicts a higher long-run yield?

Minecraft is useful because consequences can be tested repeatedly, branched and compared. That's a luxury the physical world doesn't offer. But the aim was never Minecraft. The same adaptive ability, working with incomplete models, costly experiments and shared knowledge, is what we'd eventually want to understand in the real world.