# An investigation of model-free planning

arXiv: https://arxiv.org/abs/1901.03559 · HTML: https://mlsanity.com/paper/1901.03559/

## Key facts

- Cited by 66 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 11 Jan 2019.

## Built on by (most cited first, 30 of 66)

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- [Muesli: Combining Improvements in Policy Optimization](https://mlsanity.com/paper/2104.06159/) (2021)
- [Relational Attention: Generalizing Transformers for Graph-Structured Tasks](https://mlsanity.com/paper/2210.05062/) (2022)
- [Procedural Generalization by Planning with Self-Supervised World Models](https://mlsanity.com/paper/2111.01587/) (2021)
- [Subgoal Search For Complex Reasoning Tasks](https://mlsanity.com/paper/2108.11204/) (2021)
- [Neural Algorithmic Reasoners are Implicit Planners](https://mlsanity.com/paper/2110.05442/) (2021)
- [Policy-Guided Heuristic Search with Guarantees](https://mlsanity.com/paper/2103.11505/) (2021)
- [Megaverse: Simulating Embodied Agents at One Million Experiences per Second](https://mlsanity.com/paper/2107.08170/) (2021)
- [There Is No Turning Back: A Self-Supervised Approach for Reversibility-Aware Reinforcement Learning](https://mlsanity.com/paper/2106.04480/) (2021)
- [Planning in a recurrent neural network that plays Sokoban](https://mlsanity.com/paper/2407.15421/) (2024)
- [HALMA: Humanlike Abstraction Learning Meets Affordance in Rapid Problem Solving](https://mlsanity.com/paper/2102.11344/) (2021)
- [Hierarchical Imitation Learning with Vector Quantized Models](https://mlsanity.com/paper/2301.12962/) (2023)
- [High-Accuracy Model-Based Reinforcement Learning, a Survey](https://mlsanity.com/paper/2107.08241/) (2021)
- [Thinker: Learning to Plan and Act](https://mlsanity.com/paper/2307.14993/) (2023)
- [Fast and Precise: Adjusting Planning Horizon with Adaptive Subgoal Search](https://mlsanity.com/paper/2206.00702/) (2022)
- [Transcendental Idealism of Planner: Evaluating Perception from Planning Perspective for Autonomous Driving](https://mlsanity.com/paper/2306.07276/) (2023)
- [GameTraversalBenchmark: Evaluating Planning Abilities Of Large Language Models Through Traversing 2D Game Maps](https://mlsanity.com/paper/2410.07765/) (2024)
- [Levin Tree Search with Context Models](https://mlsanity.com/paper/2305.16945/) (2023)
- [What model does MuZero learn?](https://mlsanity.com/paper/2306.00840/) (2023)
- [Integrating Symmetry into Differentiable Planning with Steerable Convolutions](https://mlsanity.com/paper/2206.03674/) (2022)
- [Scaling up and Stabilizing Differentiable Planning with Implicit Differentiation](https://mlsanity.com/paper/2210.13542/) (2022)
- [Trust-Region Twisted Policy Improvement](https://mlsanity.com/paper/2504.06048/) (2025)
- [When Can Model-Free Reinforcement Learning be Enough for Thinking?](https://mlsanity.com/paper/2506.17124/) (2025)
- [SPO: Sequential Monte Carlo Policy Optimisation](https://mlsanity.com/paper/2402.07963/) (2024)
- [Solving Sokoban with forward-backward reinforcement learning](https://mlsanity.com/paper/2105.01904/) (2021)
- [FoMo Rewards: Can we cast foundation models as reward functions?](https://mlsanity.com/paper/2312.03881/) (2023)

## Abstract (arXiv)

The field of reinforcement learning (RL) is facing increasingly challenging domains with combinatorial complexity. For an RL agent to address these challenges, it is essential that it can plan effectively. Prior work has typically utilized an explicit model of the environment, combined with a specific planning algorithm (such as tree search). More recently, a new family of methods have been proposed that learn how to plan, by providing the structure for planning via an inductive bias in the function approximator (such as a tree structured neural network), trained end-to-end by a model-free RL algorithm. In this paper, we go even further, and demonstrate empirically that an entirely model-free approach, without special structure beyond standard neural network components such as convolutional networks and LSTMs, can learn to exhibit many of the characteristics typically associated with a model-based planner. We measure our agent's effectiveness at planning in terms of its ability to generalize across a combinatorial and irreversible state space, its data efficiency, and its ability to utilize additional thinking time. We find that our agent has many of the characteristics that one might expect to find in a planning algorithm. Furthermore, it exceeds the state-of-the-art in challenging combinatorial domains such as Sokoban and outperforms other model-free approaches that utilize strong inductive biases toward planning.
