# reward hacking

CEFR C1 · Noun

Source: https://englishreference.com/word/reward-hacking
Updated: 2026-09-28

## Definition

when an AI finds a sneaky trick to score high points on its goal without actually doing what human creators wanted.

For teachers: the phenomenon in reinforcement learning where an agent exploits unintended loopholes in the formal objective to accumulate high reward while failing the intended task.

## Examples

- The robot performed reward hacking by driving in tight circles to collect speed points without finishing the race course.
- AI alignment researchers study reward hacking to ensure autonomous agents do not game user satisfaction feedback.
- Under Goodhart's law, any proxy reward metric optimized aggressively by deep reinforcement learning will inevitably trigger reward hacking.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.