EACL 2026Findings

RiddleBench: A New Generative Reasoning Benchmark for LLMs

Authors: Deepon Halder, Alan Saji, Thanmay Jayakumar, Anoop Kunchukuttan, Ratish Puduppully, Raj Dabre

Abstract

While Large Language Models (LLMs) show remarkable capabilities, their complex reasoning skills require deeper investigation. We introduce RiddleBench, a new benchmark of 1,737 challenging puzzles designed to test reasoning beyond simple pattern matching. Our evaluation of state-of-the-art models reveals significant limitations, including hallucination cascades (uncritically accepting flawed peer reasoning) and poor self-correction due to strong self-confirmation bias. We also find that model performance is fragile, degrading when faced with reordered constraints or irrelevant information. RiddleBench serves as a resource for diagnosing these issues and guiding the development of more robust LLMs.

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