NetHack Learning Environment (NLE)
DeepMind / FAIR's NetHack Learning Environment — a Gym-compatible interface to NetHack, the canonical roguelike. Massive procedural state space, permadeath, deep item / skill interactions, ASCII partial-observability. Released at NeurIPS 2020; canonical long-horizon partial-observability RL benchmark.
Active · Verified 2026-05-14 · fresh as of 2026-05-14 · 31 cited facts, 0 with a third-party source · Suggest a correction
At a glance
- Tier
- T2
- Section
- Memory benchmarks & evaluation
- Created
- 2020-06 (Küttler et al. NeurIPS 2020) repo fix
- Latest release
- v0.9.x series (active as of 2024) repo fix
- License
- NetHack General Public License repo fix
- GitHub
- 1.0k★ Python/C repo fix
- Pricing
- not applicable — open benchmark; free to use repo fix
- Funding
- not applicable — not commercial fix
- Freshness
- 2026-05-14 fix
- Layer
- agent-infra repo fix
Memory taxonomy
- storage
- n/a
- retrieval
- n/a
- persistence
- n/a
- update
- read-only
- unit
- n/a
- governance
- n/a
- conflict
- n/a
When to use
Optimised for: not applicable - eval dataset, not a system
Anti-fit: not applicable - eval dataset, not a system
Pros & cons
Pros
Massive (10^48+) state space + long horizon (10^4-10^5 steps) makes it one of the hardest RL benchmarks; ASCII representation is interpretable; procedural so memorisation cannot solve it.
Cons
Sparse reward + dense procedural complexity → RL still hard-stuck at sub-human levels; ASCII-only modality limits transfer to multimodal agents.
Claims & capabilities
NeurIPS 2020 paper; NetHack Challenge run at NeurIPS 2021. After 4 years still considered unsolved at expert-human level by autonomous agents.
Technical surface
- API surface
- not applicable — eval dataset, not a system
- Backend storage
- not applicable — eval dataset, not a system
- Deployment
- not applicable — run locally
- Embedding model
- not applicable — eval dataset, not a system
- Multi-tenancy
- not applicable — eval dataset, not a system
- MCP
- not applicable — benchmark / evaluation harness
- A2A
- not applicable — benchmark / evaluation harness
- OpenTelemetry
- not applicable — benchmark / evaluation harness
Similar systems
Other memory benchmarks & evaluation in the catalog, ranked by inbound references.
- LoCoMo T3
Conversations spanning up to 35 sessions / 300 turns / ~9K tokens, built from LLM-agent personas grounded on temporal event graphs and verified by human annotators. Tests QA (single-hop, multi-hop, temporal, commonsense, adversarial), event-graph summarisation, multimodal dialogue.
- GAIA T3
Benchmark for general AI assistants made of real-world questions that require reasoning, multimodality, web browsing and tool use, with a public leaderboard on Hugging Face. Traction: ~917 likes on the Hugging Face dataset
- LongBench T3
Tsinghua THUDM. 21 datasets across 6 categories (single-doc QA, multi-doc QA, summarisation, few-shot ICL, synthetic, code completion) in English + Chinese. ~6.7K words English / 13.4K chars Chinese average. v2 at ACL 2025 with harder, longer instances.
- LongMemEval T3
5 core memory abilities — info extraction, multi-session reasoning, temporal reasoning, knowledge updates, abstention — via 500 curated questions in synthetic chat histories. Two scales: LongMemEval-S (115K tokens), LongMemEval-M (up to 1.5M).
- RULER T3
NVIDIA. Extends NIAH with multi-needle retrieval, multi-hop entity tracing, aggregation, QA — configurable for arbitrary length / difficulty. Evaluated 17 long-context models on 13 tasks.
- InfiniteBench (∞Bench) T3
Tsinghua / OpenBMB. First benchmark with average input >100K tokens. 12 tasks across English + Chinese: long novel QA, code debugging, math in long context, summarisation, retrieval. Realistic documents (novels, code) rather than synthetic filler.
Sources (30 cited facts, 0 third-party)
Each fact links to the page it came from; the badge says who published it (how to read sources).
- What it is Roguelike RL benchmark — NetHack as agent environment repo
- What it does & what's distinct DeepMind / FAIR's NetHack Learning Environment — a Gym-compatible interface to NetHack, … repo
- Claims / benefits NeurIPS 2020 paper; NetHack Challenge run at NeurIPS 2021. After 4 years still considere… repo
- Modalities text/ASCII glyph grid + numeric stats repo
- Created 2020-06 (Küttler et al. NeurIPS 2020) repo
- Latest release v0.9.x series (active as of 2024) repo
- License NetHack General Public License repo
- GitHub 1.0k★ Python/C repo
- Mindshare canonical roguelike RL benchmark; cited by Dreamer, MuZero, IMPALA follow-ups repo
- Citations 200+ cites — NeurIPS 2020 paper repo
- Pricing not applicable — open benchmark; free to use repo
- Deployment not applicable — run locally repo
- Founders / pedigree Heinrich Küttler, Nantas Nardelli, Alexander H. Miller, Roberta Raileanu, Marco Selvatic… repo
- Reproducibility Independently reproduced — community NetHack Challenge 2021 repo
- Code/weights release Code public + game-engine source open repo
- Versioning not applicable — static benchmark repo
- Tombstoning not applicable — static benchmark repo
- Schema evolution not applicable — fixed evaluation dataset repo
- Forgetting policy not applicable — static benchmark repo
- Pros Massive (10^48+) state space + long horizon (10^4-10^5 steps) makes it one of the hardes… repo
- Cons Sparse reward + dense procedural complexity → RL still hard-stuck at sub-human levels; A… repo
- Project & sources github.com/heiner/nle NeurIPS 2020 paper repo
- commit-trajectory [{"ym":"2019-11","cum":8868},{"ym":"2019-12","cum":8943},{"ym":"2020-01","cum":8997},{"y… repo
- download-trajectory [{"ym":"2025-11","monthly":4450,"cum":4450},{"ym":"2025-12","monthly":1044,"cum":5494},{… registry
- cost-input-usd-per-mtok 0 repo
- cost-output-usd-per-mtok 0 repo
- cost-tier free repo
- cost-pricing-model free-tier repo
- cost-last-verified 2026-06-29 repo
- taxonomy-three-layer-rollup agent-infra repo