Benchmarking Large Language Models for Game Localization Quality Assurance: A Cross-Model, Cross-Lingual Analysis
Summary
Reviewing translated game text by hand is slow and costly. It has also been unclear how well LLMs can automate this localization quality assurance (LQA) across different models, target languages and game genres. The authors build a bug-seeded benchmark from professionally localized strings of three commercial games released before 2023: one RPG and two strategy titles. They inject errors using 16 rule-based patterns at three difficulty levels, covering linguistic, technical and cultural problems. This yields a 143,665-sample corpus. From it they draw 48,000 items spanning eight LLMs (closed-source and open-weight), six target languages and two genres. Each item is a binary bug/no-bug decision scored with F1. Detection runs in a pipeline that pairs cheap rule-based flagging with LLM re-validation. Claude Sonnet 4 performs best, ahead of Qwen-2.5-72B and Gemini 2.0 Flash. Neither target language nor genre significantly changes accuracy, although Japanese is the hardest language and French the most stable. The study offers studios evidence-based guidance for choosing LQA models under quality and budget constraints.
Key points
- Benchmark setup: 96 settings (8 models × 6 languages: zh, ja, ko, fr, de, es × 2 genres) with 500 samples each.
- The corpus is roughly 80% clean and 20% bug-seeded.
- Positive rates per setting range from 6% to 32%, about 19% overall.
- Bugs are split by difficulty into 35% easy, 46% medium and 19% hard.
- Models tested: Claude-Sonnet-4, GPT-4o, Gemini-2.0-Flash, GPT-4o-mini, DeepSeek-v3, Llama-3.3-70B, Qwen-2.5-72B and Mixtral-8x22B. All were queried with January 2026 API versions at temperature 0.1.
- Top results: Claude Sonnet 4 reached F1 = 0.766, Qwen-2.5-72B 0.711 and Gemini 2.0 Flash 0.691. The effect of target language was not significant (p = 0.285).
- Cost: Qwen-2.5-72B is presented as a much cheaper open-weight alternative with competitive quality. The conclusion names Gemini-2.0-Flash as the best overall cost–performance tradeoff.
- Real-world check: the top three models were tested on 500 real bug reports from two studios.
- Their rankings matched the benchmark closely (Spearman ρ = 0.89).
- Absolute F1 was 4–6 points lower than on the benchmark.
- The authors therefore advise expecting a 5–10% performance drop in production.
Cite
@inproceedings{tian2026benchmarking,
title = {{Benchmarking Large Language Models for Game Localization Quality Assurance: A Cross-Model, Cross-Lingual Analysis}},
author = {Tian, Mao and Wu, Na},
booktitle = {Proceedings of the 17th Conference of the Association for Machine Translation in the Americas (Volume 1: Research Track)},
year = {2026},
url = {https://aclanthology.org/2026.amta-research.12/}
}References
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