PRL: Prompts from Reinforcement Learning

Paweł Batorski, Adrian Kosmala, Paul Swoboda


Abstract
Effective prompt engineering remains a central challenge in fully harnessing the capabilities of LLMs. While well-designed prompts can dramatically enhance performance, crafting them typically demands expert intuition and a nuanced understanding of the task. Moreover, the most impactful prompts often hinge on subtle semantic cues, ones that may elude human perception but are crucial for guiding LLM behavior. In this paper, we introduce PRL (Prompts from Reinforcement Learning), a novel RL-based approach for automatic prompt generation. Unlike most prior methods, PRL can also generate novel few-shot demonstrations rather than selecting only from examples seen during training. Empirically, our approach achieves state-of-the-art performance across a diverse set of benchmarks, including text classification, text simplification, and mathematical reasoning, while remaining competitive on text summarization. Our code is available at https://github.com/Batorskq/prl.
Anthology ID:
2026.findings-emnlp.6
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
95–114
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.6/
DOI:
Bibkey:
Cite (ACL):
Paweł Batorski, Adrian Kosmala, and Paul Swoboda. 2026. PRL: Prompts from Reinforcement Learning. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 95–114, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
PRL: Prompts from Reinforcement Learning (Batorski et al., Findings 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.findings-emnlp.6.pdf