Steam runs an automated system that watches all game review activity across the platform in near real time, looking for sudden unusual spikes that might indicate a coordinated attack — sometimes called a "review bomb." When the system spots something strange, it flags the game for a human team at Valve to investigate. Valve announced and began enforcing this system in March 2019.

The system works in two stages. First, the automated anomaly detection tool runs continuously across the entire Steam catalog and identifies games experiencing statistically unusual review patterns — without attempting to determine the cause. Second, a human team at Valve reviews flagged cases and decides whether the spike constitutes an "off-topic review bomb," meaning the reviews are not about the game itself. If confirmed, Valve marks the affected time period, notifies the developer, and excludes those reviews from the public score summary — though the individual reviews remain visible to users who want to read them. Valve intervened in 44 cases in 2019 alone. There is no confirmed system for detecting AI-generated fake reviews specifically, despite growing concern in the community: external analysis in 2025 identified increasing numbers of AI-generated reviews on the platform.