How the scare score Works: From Head-to-Heads to a Number

The scare score is a number from 0 to 10 that says how scary a film was to you, and you never type it. You answer a short run of "Which was scarier?" questions against films you have already ranked, and the score falls out of where the film lands in your list. This guide explains every step of that, why it is built this way, and what the number does and does not mean.

Why you never type a number

Ask ten people to rate The Exorcist (1973) out of ten and you get ten different scales. One person's 7 is a film that made them sleep with the lights on. Another's 7 is "pretty good, I guess". Typed scores are easy to give and nearly impossible to compare, even with yourself across a few years. People drift. A 6 in January is not a 6 in October.

A comparison does not drift the same way. "Was Hereditary (2018) scarier than The Conjuring (2013), for you?" has an answer that you can usually give in under a second, and it stays stable because it is anchored to two specific experiences rather than to an imaginary ruler. Gasper builds your whole list out of answers like that. The number is a consequence of the order, not an input to it.

This is also why the app is horror only. "Which was scarier?" is a fair question between any two horror films. It is a strange question between a horror film and a romantic comedy.

Step one: the scare verdict

When you tap Rank on a film, the first thing you see is not a comparison. It is a single question, "How scary was it?", with three answers: Terrifying, Some scares, or Barely flinched. It is a gut call on fear, and fear alone.

The answer decides which films the new one is compared against and the range its score can land in: Terrifying from 7.0 to 10, Some scares from 4.0 to 6.9, Barely flinched from 1.0 to 3.9. A film you call Terrifying is only compared against other films you called Terrifying, and it can never end up below a film you marked Barely flinched. This matters more than it sounds. Without the answer, a single careless tap in the head-to-heads could drop a film you found terrifying below one that bored you. With it, the worst a bad tap can do is shuffle the film within its range.

It also keeps the comparisons short. If your list has eighty films and twenty of them are Terrifying, the app only needs to search twenty.

Between the verdict and the comparisons there is a card for anything worth remembering: a review with a "Contains spoilers" switch if you want one, who you watched with, tags like Jump scares or Slow burn, the "Loved this?" heart, and "Stealth mode" to keep the rank off the feed. None of it changes the score.

Step two: which was scarier?

Now the head-to-heads. Gasper shows the new film beside one you already ranked with the same answer and asks "Which was scarier?". Tap the poster that scared you more, or drag toward it. The app then picks another film from your list, closer to where the answer suggests the new one belongs, and asks again.

A few things help here. Answer about your experience, not the film's reputation. Answer from memory of how you felt, not how you think you should have felt. And answer fast. The first instinct is almost always the honest one, and the second thought is usually about what someone else would say.

When the two films feel equally scary, pick either. The scores are one decimal, so two films that sit next to each other will be a tenth of a point apart at most, and you can always re-rank later.

That is the only run of comparisons. Scare is the one thing Gasper ranks, so there is no second round about quality. When the range closes, the film is added to your rankings and the scare score animates in with its place in your list.

Binary insertion, in plain terms

The method under the hood is a binary search, the same idea you use when you guess a number between one and a hundred and someone tells you "higher" or "lower". Each answer eliminates half of what remains.

Say your Terrifying range holds sixteen films. Gasper first shows you the one in the middle. Scarier than that? Now there are eight candidates. It shows you the middle of those eight. Scarier? Four left. Then two. Then one. Four questions, and the film is placed among sixteen with no ambiguity. A range of thirty-two takes five questions; sixty-four takes six. The number of comparisons grows slowly even as your list grows fast, which is why ranking never becomes a chore.

The order is the data. The score out of 10 is just that order mapped onto the range your answer chose, with one decimal, so the number you see on a film is a reading of its position among everything you have ranked. Move the film, and the number moves with it. Rank new films around it, and its number can shift a little even though you never touched it, because the neighborhood changed.

Why early scores wobble

Gasper scores a film by comparing it to the others you have ranked, so it needs 5 ranked films before it shows numbers at all. Until then the number is blurred and the app says how many more films to rank to unlock your scare scores, which is an honest label, not a bug. Even just past that line the numbers wobble: a film that is the scariest of six you have ranked is at the top of a very short list, and whether that means a 9.8 or a 7.4 depends on what you rank next.

The numbers settle as the list fills in. By the time you have a few dozen films ranked, the scores stop drifting much, because each new film has plenty of neighbors to be placed between. Our advice is to rank the extremes early. Log the scariest thing you have ever seen and the least scary horror film you have sat through, and the middle sorts itself out.

If you want a plan for working through a backlog without wrecking the order, read Building your horror rankings.

Scare score versus the heart

Every film in your rankings carries one number, the scare score, shown with skulls. It measures how scary, and only that. For the other thing a horror fan wants to say about a film, there is the heart.

The separation matters because the two things are honestly different. The Blair Witch Project (1999) frightened a generation, and plenty of people would not call it a great film. Evil Dead II (1987) is a riot that very few people find scary, and it is a great film. On a single typed scale you have to squash those two facts into one number. On Gasper you do not: Blair Witch sits high on your list, Evil Dead II sits low and gets a heart.

The heart is one bit, loved or not. Tap it on the result screen, in the details card, or any time from the film's page, and the film is marked as loved, which the Rankings tab on your profile can filter to. It is not a ranked list and it never moves a score. The Loved it heart page goes further into how the heart works.

Re-ranking and changing your mind

Your opinion of a film is allowed to change. You watch it again, older, and it lands differently. Or you ranked it in a hurry and have been bothered by where it sits ever since. Open the film, tap Ranked and choose Re-rank head-to-head. You get a fresh verdict and a fresh run of head-to-heads, the film moves to its new position, and the score updates.

Re-ranking does not move any other film directly, though the numbers near the move can shift by a tenth, because scores are derived from order. There is no limit on how often you can do it. A list you never revise is a list you have stopped believing.

The Community Scare

Every film page shows the Community Scare: the average scare score of everyone who ranked that film, next to the percentage who loved it and your own number. Your rankings feed that average only as an anonymous aggregate. No one can see your score on a film from the community figure, and the rank reaches the feed only if you leave Stealth mode off.

The Community Scare is also what your Scare Tolerance is measured against. Score films higher than the crowd and you scare more easily; lower and you are harder to rattle. Neither is better. One of the quiet pleasures of the app is watching a film you found tame sit at a high Community Scare, and knowing that you are the outlier, with a number to prove it.