A trustworthy movie review comes from a named critic whose track record and outlet are vetted, discloses any financial or access ties to the film, and sits inside a score that reflects enough reviews to mean something. Aggregator scores add a second layer: they're convenient, but each one hides judgment calls about which critics count and how much. Knowing how Rotten Tomatoes, Metacritic, and IMDb actually build their numbers — and what U.S. regulators now require of individual reviewers — lets a reader tell a reliable signal from a thin or manipulated one.
Table of Contents
- How Rotten Tomatoes Decides Who Counts as a Critic
- What "Certified Fresh" and "Must-See" Actually Guarantee
- Why Metacritic's Number Isn't a Simple Average
- What IMDb's User Rating Doesn't Tell You
- What U.S. Rules Require Reviewers to Disclose
- Frequently Asked Questions
How Rotten Tomatoes Decides Who Counts as a Critic
Rotten Tomatoes doesn't list every reviewer who publishes an opinion. Writers earn "Tomatometer-approved" status only after meeting published eligibility rules: roughly two years of steady output, and for someone running an independent site, either 200,000+ monthly unique visitors verified through SimilarWeb or 5,000+ newsletter or Substack subscribers, according to Rotten Tomatoes' criteria page. That bar filters out reviews from brand-new blogs or small social accounts, regardless of how sharp the writing is.
A smaller group within that pool carries the "Top Critic" label. Unlike general approval, Top Critic status is assigned by an internal selection panel using separate, non-public criteria, and it cannot be applied for, per Rotten Tomatoes' FAQ. A review tagged Top Critic has passed two layers of vetting rather than one. For a reader, that distinction matters when a film's score looks surprising: checking whether the reviews behind it come from approved critics, Top Critics, or just any aggregated write-up tells you how much selectivity actually sits behind the number.
What "Certified Fresh" and "Must-See" Actually Guarantee
Both major aggregators attach a special badge once a film clears a second, higher bar than the raw score shown on the page. On Rotten Tomatoes, a film becomes "Certified Fresh" only at 75% approval or higher, with at least five Top Critic reviews counted and a minimum total review count that scales with release type — 80 or more reviews for a wide release, per Rotten Tomatoes' criteria and FAQ pages.
A 90% score built on eight reviews doesn't qualify; a 76% score built on 85 does. Metacritic runs a parallel threshold for its "Must-See" label: a Metascore of 81 or higher with at least 15 reviews counted, according to Metacritic's Metascore explanation. Below either volume floor, the badge simply doesn't appear, even if the visible percentage looks identical to a badged film.
- Check the review count next to any score, not just the percentage.
- Treat a high score with a small sample as provisional — it can move once more reviews land.
- A badge (Certified Fresh, Must-See) tells you the sample size cleared a threshold; the raw score alone doesn't.
Why Metacritic's Number Isn't a Simple Average
Metacritic's Metascore looks like a plain average of critic grades, but it isn't. The company converts each review to a numeric score, then applies a weighted formula based on what it calls an outlet's "quality and overall stature" — a formula it states it will "absolutely not" disclose, according to Metacritic's own Metascore explanation. Two films with identical raw critic scores can post different Metascores depending on which outlets reviewed each one.
Metacritic also requires a minimum of four critic reviews before it publishes a score at all, per the same source. That means a score posted in the first day or two after release — often while only a handful of outlets have filed — can shift substantially as wider coverage arrives, since each additional review carries more relative weight in a small sample. A reader comparing two films' Metascores is comparing two outputs of an undisclosed weighting system, not two raw averages. The number is still useful as a directional signal, but it isn't arithmetic you can double-check by hand.
What IMDb's User Rating Doesn't Tell You
IMDb's star rating looks like a simple average of user votes, but IMDb states publicly that it's a "weighted vote average," not a raw mean, and that it withholds the exact weighting method specifically "to ensure that our rating mechanism remains effective" against manipulation, as reported by Variety. The company doesn't explain which votes get discounted or by how much. That system can swing a score dramatically.
After an "unusual" surge of negative voting hit "The Little Mermaid" in 2023, IMDb's weighted calculation raised the film's rating from roughly 4.7 out of 10 unweighted to about 7 out of 10 weighted, per the same Variety/CBS News reporting. The gap between those two numbers shows how much of a coordinated voting campaign the weighting absorbed — and how far a raw count can drift from what IMDb actually displays. For a reader, the practical lesson is that an IMDb score reacts to vote-bombing campaigns in ways the displayed number is specifically designed to resist, but the correction happens invisibly. A sudden swing in either direction, especially right after release, is worth more scrutiny than a number that has settled over weeks.
What U.S. Rules Require Reviewers to Disclose
Beyond the aggregators' own math, federal rules govern what an individual reviewer must tell readers. The FTC updated its Endorsement Guides effective 2023-06-29, requiring that any undisclosed material connection between a reviewer and the thing being reviewed — payment, free access, or an affiliation with the studio or distributor — be disclosed clearly and conspicuously, according to a Hogan Lovells summary of the update. The agency went further the next day: a rule proposed 2023-06-30, and later finalized, bans writing, buying, or selling fake reviews — including reviews attributed to people who never saw the film — and bans suppressing genuine negative reviews, with civil penalties attached for violators, per summaries of the FTC rulemaking.
A reviewer who received free festival travel, an early screening perk, or payment from a studio is now required to say so. A score on an aggregator site tells you how many people counted something as positive; it doesn't tell you who those people are, what counted as a "review," or whether anyone had a stake in the outcome. Reading the badge thresholds, the weighting caveats, and the disclosure line together is what separates a number from a verdict.
- Look for a disclosure line near the byline on individual reviews, especially around festival coverage or junkets.
- Treat a review with no disclosure and glowing, undifferentiated praise more skeptically, particularly for a site reviewing a studio's own content.
- A single outlet's named, disclosed review carries different legal weight than an anonymous aggregator data point — the FTC rules apply to the former, not the latter.
Frequently Asked Questions
Does a high percentage on Rotten Tomatoes mean most critics loved the film?
Not necessarily on its own — check whether the score also carries the "Certified Fresh" badge, which requires 75%+ approval, at least five Top Critic reviews, and a minimum total review count that scales with release type, per Rotten Tomatoes' criteria.
Why might two films with similar critic scores show different Metascores?
Metacritic weights each outlet by its own undisclosed "quality and overall stature" formula rather than averaging scores evenly, according to Metacritic.
Can a studio legally pay a reviewer without telling readers?
No — FTC Endorsement Guides updated 2023-06-29 require clear disclosure of any material connection, including payment or free access, per Hogan Lovells' summary.