Seizures from 2017’s best video games

What Remains of Edith Finch, Gorogoa, Everything, Night in the Woods, Divinity: Original Sin 2, Legend of Zelda: Breath of the Wild, PlayerUnknown's Battlegrounds, NieR:Automata, Persona 5, Super Mario Odyssey

The New Yorker’s Top 10 video games of 2017. Five contain scenes that could trigger seizures.

When you play a game ranked in the GameSpot or New Yorker Top 10 video games of 2017, the chances are about even that you will be exposed to images that could trigger photosensitive seizures. These images, which violate established guidelines for reducing the risk of photosensitive seizures, appear in 6 of the games in a combined Top 10 list. In 7 games these images were not found (some games are on both Top 10 lists).

What are photosensitive seizures?

Resident Evil 7, Horizon Zero Dawn, Wolfenstein 2: The New Colossus, Hellblade: Senua's Sacrifice

GameSpot’s 2017 Top 10 list includes 6 games that contain images that can trigger seizures.

Photosensitive seizures can occur when people with photosensitive epilepsy are exposed to intense visual stimuli: bright, rapid flashing light and bold patterns with strong contrasts. An unknown segment of the population has photosensitive epilepsy, including people with no history of seizures. It is under-reported and under-diagnosed.

In those who develop the condition, photosensitive epilepsy typically is hidden until the first noticeable seizure occurs in the presence of bright flashing or patterns. Most people with other types of epilepsy are not photosensitive. In other types of epilepsy, seizures are much more unpredictable.

Seizures can be of any type, from tonic-clonic episodes with loss of consciousness to brief absence seizures that can be as subtle as a brief hesitation or stare. Most people do not have photosensitive epilepsy, but many who do are unaware that they have the condition until a they experience a seizure during or after exposure to flashing or patterned images. Some individuals may have seizures that are too subtle to notice.

Screen grab from a sequence in The Legend of Zelda that could provoke a seizure in individuals with photosensitive epilepsy.

The seizure reduction guidelines test 

Guidelines for seizure reduction originated in 1994, when the UK adopted technical guidelines to accommodate TV viewers with photosensitive epilepsy. These guidelines, based on studies by photosensitive epilepsy experts, outline the characteristics of flash rates and spatial patterns that typically trigger seizures in people with photosensitive epilepsy. They were later updated and some have been adopted by the World Wide Web Consortium (WC3), the international group that produces website standards for all types of applications, and the International Telecommunication Union.

The guidelines define criteria for photosensitive seizure risk involving:

  • flash rate greater than 3 per second and less than 60
  • stripes and geometric patterns with high contrast
  • large areas of very bright (“saturated”) red
  • any of the above problem images taking up more than one quarter of the total screen area

Visuals adhering to these guidelines are unlikely to provoke seizures in 97% of people with photosensitive epilepsy.

Testing video games for compliance with guidelines

Although most games carry seizure warnings, not all games contain the types of images that can bring on seizures. The warnings are not specific to the content of a given game, so consumers who pay attention to the warning don’t know whether it pertains to the game they are about to use. So I test them.

I tested the games using downloaded clips of gameplay that I loaded into an application called the Harding Flash and Pattern Analyzer. The FPA is widely used by TV producers and networks in the UK—including by the BBC—to reduce the risk of seizures from material on broadcast TV, and is used by some game studios. It examines video sequences frame by frame for very specific and measurable image qualities that research shows can trigger seizures.

For more specifics on how to interpret the test results, please see this prior post. For more on my testing process, see this one.

New York Magazine’s Top Ten Video Games? Half ignore seizure safety guidelines!


Thumper, #9 on New York Magazine‘s top ten games list, has many flashing images that could trigger seizures in users. The image here is seen during a sequence that failed the seizure guidelines compliance test.

Five of New York Magazine’s top ten video games of 2016 don’t meet guidelines for reducing the risk of visually provoked seizures. Developers of these popular games could have designed the visuals in a way that lowers the seizure risk to users, but didn’t.

Guidelines for reducing the risk of seizures triggered by video images were published in 1994, when the UK required that all TV programs and advertisements meet those visual safety standards. The same guidelines for making television images safer could easily be adhered to when developing video game visuals. No regulations on seizure-inducing images in video games have ever been enacted, so game developers have no incentive to work within the guidelines.

Instead, for many years game publishers have provided a seizure warning that makes it extremely difficult for consumers to take legal action in case of a seizure. Some games may in fact conform to seizure-reduction guidelines, but because the seizure warnings appear on all games, consumers can’t know which ones are riskier. The warnings began appearing in 1991 in response to the first video-game-seizure consumer lawsuits.

What compliance with the guidelines means

Many popular games don’t meet the guidelines, as demonstrated by my testing of New York Magazine‘s favorite games. A couple of the failing games were among the top five first-person shooter games selected by Forbes.

Thumper, Overwatch, Hyper Light Drifter, Uncharted 4: A Thief's End, Doom, Inside, Firewatch, Kentucky Route Zero Act IV, Owlboy, Overcooked

New York magazine’s top ten video games for 2016

I tested video clips from gameplay and promotional trailers for the games on the list using software that identifies video sequences that don’t comply with the guidelines. The software is designed for game developers and video producers to test their moving images for compliance.

Note that for the games that didn’t violate the guidelines, rather than list them as passing the compliance test, I’ve indicated that they did not fail the test. Although in previous posts with test results I’ve listed games that “passed” the guidelines test, I’m no longer using that terminology. That designation could too easily be misinterpreted to mean that such games will definitely not cause seizures.

Even if a game doesn’t fail the guidelines compliance test, there is still a risk of seizures, for several reasons:

  • I may not have tested a portion of the game with problem image sequences
  • The guidelines aren’t fool-proof. They are designed to prevent seizures in approximately 97 percent of people who have photosensitive epilepsy, the condition where visual stimuli can trigger seizures.
  • Many environmental and personal health variables–such as lack of sleep or illness– can affect an individual’s vulnerability to seizures

Do you need to worry about seizures from video games?

  • The vast majority (97 percent) of people diagnosed with conventional epilepsy can play video games without risking a seizure because–unless their EEGs indicate otherwise–their seizures aren’t triggered by visual effects. These people don’t want others questioning their fitness for gaming.
  • People with no history of epilepsy may be most at risk. Seizures can be triggered by flash and flicker even in people with no history of seizures, which means that many don’t know they are at risk of having a visually triggered seizure until a video game brings on their first event. Of the children who had seizures during the 1997 Pokémon cartoon broadcast in Japan, only 24% had previously experienced a seizure.
  • Visually triggered seizures typically begin between ages 2-18, and most commonly begin around age 12-13. Of patients age 7-19 who seek medical attention for a seizure, ten percent test positive for photosensitive epilepsy. Researchers estimate that only 25 percent of people outgrow the condition, typically in their twenties.
  • It is relatively unusual but not unknown for these seizures to develop in adults. Because in many individuals a number of factors (for example, emotional state and hormone levels) affect seizure vulnerability, a seizure may not actually occur until several of these factors are present simultaneously. Even one seizure can be life-changing if it results in injury or permanently bars an individual from certain occupations.
  • It is also possible to experience subtle seizures and not realize they happened. This doesn’t mean there are no seizure consequences, though. Typically after seizures one’s physical, cognitive, and emotional functioning can be impaired.

More on the guidelines and how games are tested for seizure risk

Want to know more about how I test video games? Read here. Or read more about the image safety guidelines.

5 top first person shooter games of 2016 fail seizure safety guidelines test

None of the five video games picked by a Forbes reviewer as the year’s best first-person shooters meet safety guidelines for reducing the risk of visually triggered seizures.

The fast-moving, flashing images in these five games could provoke seizures in people whose seizures are triggered by visual stimuli, due to a sometimes hidden condition called photosensitive epilepsy. I tested image sequences from these popular games using software designed for checking the adherence of images sequences to the seizure reduction guidelines. All five failed:


Forbes’ Best 5 First-Person Shooter Games of 2016 all failed to adhere to guidelines for reducing seizures.

Game developers could — should — use this same technology to build products compliant with the guidelines! The application I used to test the games for compliance isn’t a consumer product; it’s intended for developers. Instead of building games that comply, many developers simply place seizure warnings on games and consoles. People with no history of seizures don’t pay much attention to seizure warnings, though. Why would they?

Reason #1 consumers don’t know they may be at risk 

This bright flash is seen during a Doom image sequence that fails to meet seizure reduction guidelines.

This bright flash is seen during a DOOM image sequence that doesn’t meet seizure reduction guidelines.

Photosensitive epilepsy most often develops in adolescence and remains hidden until it’s activated by particular stimuli and circumstances. If earlier in life visual stimuli didn’t trigger an event, how does one know that’s no longer true?

According to one study, 74 percent of individuals with photosensitive epilepsy first learn they have the condition when they experience a seizure in the presence of flashing lights or another visual stimulus. This study was based on the histories of hundreds of children who had seizures during a 1997 Pokémon cartoon broadcast in Japan.

Sometimes the first seizure triggered by a video game can have life-changing consequences. A Navy pilot who played Oblivion, had a seizure that produced injuries and resulted in permanent loss of his flight clearance. Think of the medical testing he underwent before he was trained to fly–obviously his seizure vulnerability had not yet developed.

Reason #2 consumers don’t know about their risk

A problem sequence in Call of Duty: Infinite Warfare is created by a flicker effect of changing background light in this scene.

A problem sequence in Call of Duty: Infinite Warfare is created by the flicker effect of alternating background light in this scene.

Some seizures aren’t noticeable. This means that included in the 74 percent who (think they) never had a prior seizure, there are some people who may already be experiencing them without realizing it. Subtle seizures involving no body movement may not draw the attention of others nearby, either.

People with no history of seizures aren’t aware that undetected seizures exist and therefore may dismiss any unusual physical or mental sensations while gaming. If the seizure causes a loss of awareness for a few seconds, the person will not be “present” at that moment to recognize what’s happening or remember it later. For more on undetected seizures, see the section “Research shows people often don’t detect their own seizures” in this post.

Note that undetected seizures as well as more obvious events can bring on a range of disabling physical and cognitive after-effects and mood changes that can linger for days.

Reason #3

When the area on the screen lit by a flash and the time interval between flashes exceed guidelines for seizure reduction, the image sequence fails the assessment. This screen shows test results for Titanfall 2.

This screen capture from the Harding Flash and Pattern Analyzer, which I used to assess guidelines compliance, shows test results above the horizontal pass/fail line.

Not all video games violate the image safety guidelines. Even though video games typically carry seizure warnings, the warnings don’t reflect the seizure risk of any particular game. Unfortunately, consumers have no way of knowing which games are in compliance and which are not.

Let’s say you’re an informed consumer, aware that some games can pose a seizure risk and you’d prefer not to take that risk. You understand that a game with lots of bright flashing is more likely to be a problem, but you can’t really know whether a specific game that you want to play is more likely to trigger seizures. How can you play only games that meet guidelines and avoid only the noncompliant ones? (This is where the testing I can do can identify certain cases of noncompliance.)


  • The vast majority (97 percent) of people diagnosed with conventional epilepsy can play video games without risking a seizure because their seizures aren’t triggered by visual effects. These people don’t want others questioning their fitness for gaming.
  • Want to know more about how I test video games? About the image safety guidelines? Read here.
  • For the record, Forbes states that opinions of contributing writers (such as this guy who picked the five games) are their own, not the magazine’s.

Safe to play a game that passes the seizure test?

I've been using charts like this one to show results of testing for adherence to photosensitive epilepsy guidelines.

Until now I’ve posted charts in this format to show whether a game meets photosensitive epilepsy guidelines…

According to a Reddit post, a game that I’ve said “passed the seizure test” triggered a seizure. Recently the same game—Hearthstone—could have been implicated in a professional gamer’s seizure that happened during a live stream. What’s going on?

I write about games I’ve tested to alert readers to the games that don’t meet internationally recognized image safety guidelines. But I don’t want to create undeserved confidence that a game that passed the seizure test will be safe for anyone with photosensitive epilepsy.

Ian Hamilton, a user interface designer who specializes in and advocates for game accessibility, clarifies the role of testing this way:

“Passing the Harding test doesn’t mean that a game is safe. It means ‘reasonably safe’ because common triggers have been avoided. Something that gets a ‘pass’ can still absolutely cause seizures.”

I regularly write that your experience may differ, that I’m not trained in quality assurance, that I test excerpts of game play, and that health and lifestyle variables affect every individual’s vulnerability to seizures at any given time. Still, the meaning of my findings could be misleading without an understanding of the limitations of the seizure test itself:

  1. the pass/fail guidelines aren’t expected to prevent seizures in all individuals
  2. the test was designed for TV images, not video games

What the Pass/Fail guidelines mean

The guidelines originated in 1994, when the UK’s agency for regulating TV broadcasting (now known as Ofcom) inserted into its code of standards some technical guidelines to accommodate viewers with photosensitive epilepsy. These guidelines, based on studies of photosensitive epilepsy and consultation with Prof. Graham Harding and other photosensitive epilepsy experts, detail flash rates and spatial patterns that typically trigger seizures in people with photosensitive epilepsy. Specifications regarding saturated red images were added later, after the 1997 Pokémon incident in Japan.

Some compromises in the guidelines were made for the sake of practicality. Criteria for acceptable images (commonly referred to as the Harding test) were developed with the understanding that they would realistically protect most individuals with photosensitive epilepsy, but not all. For example, the guidelines permit images that flash at a rate of up to 3 times per second because flash at that frequency affects only 3 percent of photosensitive individuals. UK regulators decided that was “an acceptably small risk.”

I'm taking the word "safety" out of the chart since passing the test doesn't guarantee seizure safety

…but I’m updating all the charts by removing the word “safety” since passing the test doesn’t guarantee seizure safety.

The introduction to the guidelines states that their purpose is “reducing the risk of exposure to potentially harmful stimuli.” It also concedes that even when broadcasting images that comply with the guidelines,

“it is…impossible to eliminate the risk of television causing convulsions in viewers with photosensitive epilepsy.”

Applying TV guidelines to video games

There are no formal guidelines for reducing the seizure risk from video games. A 2005 consensus paper by experts on photosensitive seizures acknowledges that additional work would be required first on the existing guidelines for TV. In the meantime, it is reasonable to use the television guidelines since the impact of screen images on the visual system is the same.

The biggest challenge in applying TV specifications to video games is explained in the consensus paper:

“These principles are easier to apply in the case of fixed media (for example, a prerecorded TV show), which can be analyzed frame-by-frame. Interactive media, such as video games, may afford essentially limitless pathways through the game, depending on user actions. Therefore …in the case of video games, the consensus recommendations apply to typical pathways of play but cannot cover every eventuality of play.”**
Also,when players set their own viewing perspectives and preferences in newer video games, they may create unanticipated seizure risks.

Reducing risk going forward

In sum, a game that fails the Harding test is best avoided by those with photosensitive epilepsy. A game that passes is less likely to act as a trigger. Despite all the qualifiers, I believe there’s value in reminding people that seizures can happen to anybody, that certain video games can trigger them, and that you can lessen the risk by selecting games without lots of flash and patterns. Other strategies to lessen the risk of photosensitive seizures can be found here and here.

Tip of the hat to Ian, who suggested that I avoid the word “safe” when describing games that have passed the test. I also will be revising my prior posts to do some rewording.

Gamer’s seizure on live stream

Here’s a reminder that seizures can happen to anyone. A professional gamer known as Lothar had a seizure recently during his live feed while playing Hearthstone on Twitch. Lothar apparently has no history of seizures and the seizure may or may not have any connection to Hearthstone. In updates about his condition and hospital stay, Lothar didn’t mention photosensitive epilepsy nor has he said he’s been advised to limit his gameplay. 

For the record, Lothar is also a body builder—he’s obviously a guy who has enjoyed good health and takes good care of himself. Lothar has a large and caring following and has been receiving lots of well wishes as he recovers. Why do I mention this incident here? Viewing the incident (you can find it on YouTube) and seeing how it affected so many fans who care about him reinforced for me the seriousness of seizures and the importance of preventing those that are preventable.

** Graham Harding et al. (2005), Photic- and Pattern-induced Seizures: Expert Consensus of the Epilepsy Foundation of America Working Group. Epilepsia, 46: 1423–1425.

Can handheld games trigger seizures?

Nintendo's 3DS console

Nintendo’s 3DS console

Think the screen of a handheld game is too small to provoke seizures?

It isn’t. Games on the 2.9 inch screen of Nintendo’s Game Boy Advance SP provoked quite a few seizures in my daughter when she owned one ten years ago. 

Nintendo’s current handheld is the popular 3DS console, which has a 3.5 inch screen. I recently tested some 3DS games to ascertain their seizure safety.  

The rule of thumb (as it were) is that, for flashing and patterns to trigger seizures, the provoking image must take up at least one fourth of an individual’s visual field. It’s not unusual for kids to hold their portable games at close enough range for that small a screen to fill that much of their total view. Incidentally, although concerns were raised when the 3DS was introduced three years ago, there isn’t any conclusive evidence that 3D effects increase the risk of seizures in people who are photosensitive.

The website recently identified the 14 most anticipated 3DS games for 2014 release. Here’s how they fared when tested for compliance with guidelines for preventing visually induced seizures; 6 of the 14 failed, and an additional 5 came close. Tests were done using the Harding Flash and Pattern Analyzer.

Here is how these highly anticipated 3DS games performed as far as meeting image safety guidelines for preventing photosensitive seizures:

Professor Layton & Azran Legacies, One Piece Romance Dawn, Mario Golf World Tour, Lego Movie, Yoshi's New Island, Super Smash Brothers, Mario Party Island Tour, CHantae & the Pirate's Curse, Retro City Rampage, Professor Layton vs Phoenix Wright, Kirby Triple Deluxe, Chi Bi-Robo Photo Finder, Bravely Default, Conception II

14 Big 3DS Games of 2014, published January 30, 2014 on

Yes, there are seizure warnings on all game packages, but the warnings are pretty worthless for consumers. A year ago I posted about Nintendo being fully aware of, but publicly downplaying, the risk of seizures from its games.

Some doctors too reassuring about seizure risk

Howcast's video, "What Is Photosensitive Epilepsy (PSE)?"

The Howcast video, “What Is Photosensitive Epilepsy (PSE)?” is apparently designed to be upbeat and reassuring to families worried about video games.

You know how you’re not supposed to trust all the medical information on the Internet? Very true, and sometimes it’s actually the medical professionals who are placing material online that is oversimplified to the point of being misleading.

Trying to explain photosensitive epilepsy in a video of a minute and a half is pretty tough, and a Howcast clip that attempts to do that is just full of statements that make me very uncomfortable. It’s one of a series of videos on different aspects of epilepsy, but the presenters, despite their epilepsy expertise, aren’t necessarily experts in the specialty of photosensitivity. Photosensitive seizures are considered so out of the mainstream of epilepsy that few epilepsy specialists know a great deal about them.

The video in question, uploaded a year ago, features a pediatric epilepsy nurse and the Director of Pediatric Epilepsy at highly respected hospitals in New York City. My own qualifications for assessing the content of their video are found here.  I’m quite certain that I’ve read more of the research on photosensitive epilepsy and seizures triggered by video games than anyone on the planet who isn’t a photosensitive epilepsy specialist. There are very, very few photosensitivity experts in the US.

This video downplays the overall prevalence/likelihood of photosensitive seizures, and it doesn’t address photosensitivity in people with no other seizures. And it overstates the conclusiveness of EEG for identifying seizure activity. Epilepsy clinicians and advocacy groups tend to want to reassure young patients and their families that in the vast majority of cases, video games and other flash-filled leisure pursuits don’t pose a seizure risk. While it’s good to encourage patients to live lives that are as normal as possible, the oversimplified message promotes the view that photosensitive epilepsy is quite rare and that doctors can know for sure, based on EEG testing, whether an individual should worry about video games as a seizure risk.

If you want to watch the video, please come back here to read my responses to what’s in it! Here’s a transcript with my comments in blue.

————————————————————————————————————————————————————————————————————-Nurse: “You know, whenever anybody comes into the office, they always ask us first thing whether epilepsy can be triggered by strobe lights, and people often think back to when the first Pokemon movies came out and all those children in Japan seized during the movies. So photosensitive epilepsy is something people worry about all the time.”


Two issues here:

1) Epilepsy is a condition that makes people vulnerable to seizures. It’s the seizures that are triggered; the epilepsy condition already exists. Why take issue with such a seemingly minor point? Being less than careful in how she worded things allowed a doctor in a WebMD video to incorrectly reassure viewers that video games cannot cause seizures!

2) The problem is much bigger than the population of epilepsy patients who come in to be evaluated by neurologists–people with no seizure history may develop photosensitive epilepsy (for example, the Navy pilot who can’t ever fly again after having a grand mal seizure while playing Oblivion: The Elder Scrolls IV). The general public, though–which presumably is the audience for this video–doesn’t worry enough about it. The epilepsy community should be doing more outreach to the general public to let them know they could be at risk.


Doctor: “On all the video games there’s those warnings that say, you know, you shouldn’t play this game in case you have epilepsy. But only one specific type of epilepsy has photosensitivity to it, and that’s a generalized epilepsy, that’s when the whole brain turns on all at once–”


This is what neurologists believed in the past.  But numerous studies in the last 20+ years show this is not the case. A 1994 paper that included a review of other studies concluded that about 30 percent of photosensitive seizures are partial seizures—which do not involve the whole brain. The doctor’s statement could lead viewers to think that only people with generalized (typically grand mal) seizures need to worry about photosensitivity.


Nurse:…”lights up all at once, there’s a big burst of electricity through the whole brain. It’s one of the reflex epilepsies, so kids for the most part with epilepsy can play video games and can go under strobe lights unless they very specifically seize when they’re under strobe lights, and when we do the EEGs, we do the tests of their brain waves, we actually flash lights at them to see if it does create a seizure.”


The intermittent photic stimulation procedure used during EEG measures the brain’s reaction to a strobe light. The effect of a strobe light on the brain is not equal to the effect of playing a fast-moving, flashing video game. Some people who don’t respond to the strobe light can have seizures in response to video games or other visual stimuli. Studies of video game seizures frequently include individuals who experience seizures from games but do not test positive for photosensitivity. Photosensitive epilepsy in the research literature describes epileptic discharges on EEG in response to a strobe light in a laboratory. Some studies discuss non-photosensitive video game seizures: people who have the seizures even though a strobe light doesn’t produce signs of epilepsy on an EEG.  


Doctor: “So by doing the EEG and flashing the lights in the child’s eyes, and having the EEG run at the same time, we can conclusively tell families whether the children can play video games or not play video games, and that will make a child very happy, hopefully finding out that it’s perfectly safe to play the video games and that they don’t have photosensitive epilepsy.”


EEG doesn’t conclusively rule out any type of seizure! It can confirm seizures but cannot rule them out since the technology does not detect all seizure activity. Some people who have seizures have normal EEGs. Oddly enough, in another video, What’s the Difference between Seizures and Epilepsy?” featuring the same clinicians in the same Howcast series, they contradict their statements in the first video, conceding that some seizures are too located too deep inside the brain to be detectable by EEG on the scalp.  

7/19/2014 update: See information on a study showing just 6.2 percent of patients with visually induced seizures tested positive for photosensitivity in the photic stimulation EEG procedure.


Nurse: “As well as the teenagers and the young adults who will call or text and say, “Can I go–we’re going to a party and I know there’s going to be strobe lights. Is that OK?” So at least we have an answer for them after we’ve done the initial EEG.


Photosensitive epilepsy is a genetic trait that is dormant until it becomes activated by a combination of factors. The most common time for the disorder to emerge is in adolescence. Thus a child who shows no signs of photosensitivity (again, based on testing with strobe lights, not video games) may later experience photosensitive seizures.

We need epilepsy clinicians and advocacy organizations to:

  • be more concerned about the many visual stimuli in our environment that can trigger seizures
  • think more broadly about who may be at risk–including members of the public who have no other seizures
  • convey their concern about hazardous visual stimuli to the public, the digital entertainment industry, and lawmakers
  • push for public policy changes that will rein in the stimuli and reduce the occurrence of visually triggered seizures.
  • question reliance on EEG and photic stimulation to diagnose vulnerability to visually induced seizures

It’s a big job. It’s a much bigger undertaking than I can even imagine, but it needs to be done.