CNET endorses 7 video games that can trigger seizures

Uncharted: The Nathan Drake Collection is the only one of CNET's recommended games where I didn't find image sequences that can provoke seizures.

Uncharted: The Nathan Drake Collection is the only one of CNET’s recommended games that didn’t fail the seizure test.

Wouldn’t it feel terrible to give someone a present that could set off an epileptic seizure? If you consult the CNET guide to video games for 2015 holiday giving, you’ve got 8 games to choose from–of which 7 contain seizure-inducing images. In the 3+ years that I’ve been testing selected video games for seizure-provoking graphics, this is easily the most lopsided result I’ve found.

The following table shows the games recommended in CNET’s “The best video games to give this holiday season” feature, with results of testing them for image sequences capable of triggering seizures. Testing is done with an application designed for this specific purpose (more info on that is below in the testing methdology section).

Uncharted: The Nathan Drake Collection, Call of Duty: Black Ops 3, Fallout 4, Halo 5: Guardians, Just Cause 3, Super Mario Maker, Star Wars Battlefront, Rise of the Tomb Raider

CNET’s choices for best video games to give this holiday season

Interpreting the results

Passing the seizure guidelines test means that in the 1.5+ hours of gameplay and cutscenes I tested, all image sequences meet well-defined guidelines for reducing visually induced seizures. I am not set up to test every possible sequence (video game developers should be able to do this, though). To get a “fail” on my tests, all that’s needed is one violation of the guidelines, which could occur within the space of a second or two. Again, since I do not test every possible sequence, it’s very possible–and likely–that the game also has other problem images that I didn’t test.

Your results may be different. Each person’s seizure threshold can be affected by a number of factors apart from the visual stimulus itself: illness, hunger, stress, fatigue, alcohol, medications, length of play, and others. So a game played without incident may trigger a seizure in the same player under different conditions. Also, players can be exposed to new and different image sequences in subsequent games.

CNET selected conventional action/adventure titles for its gift-giving guide. These games typically have plenty of shooting, explosions, and rapid movements that produce flicker in the seizure-inducing range of more than 3 flashes per second. In contrast, recent video game recommendations from both the New York Times and Los Angeles Times, with less tech-focused audiences, added some unconventional titles to their top picks. It’s worth noting that the less traditional games were less likely to fail the seizure test.

Uncharted: The Nathan Drake Collection–the one game CNET chose that meets the seizure reduction guidelines–is an action/adventure game, too, with some shooting and the occasional explosion, but designed without flickering images or other visual overload.

 Call of Duty Black Ops 3 Fallout 4 Halo 5: Guardian Just Cause Super Mario Maker Star Wars Battlefront Rise of the Tomb Raider

Images in Uncharted: The Nathan Drake Collection show explosions yet stay within seizure prevention guidelines.

Why it matters

Nobody wants to think about the risk of seizures that can be triggered by video games, figuring they’re extremely rare (they aren’t) and that the risk only applies to “people with epilepsy” (not so). Also, people assume that seizures are always of the grand mal type, with loss of consciousness, lots of involuntary movements, etc., so that they would be very obvious events (most seizures are not like this).

If you assume seizures are very obvious, then you also assume you’d hear a lot more about seizures that happen in front of computer screens and consoles. But many seizures are much more subtle, some so subtle that nobody realizes they’re happening. Even in these instances, though, the after-effects may mean impaired functioning for up to several days, or longer, affecting energy, concentration, memory, sleep, and mood. You can read here about how game-induced seizures we couldn’t see affected my daughter.

Vulnerability to seizures from bright flashes and rapid flicker, known as photosensitive epilepsy, is a genetic trait that’s latent in an unknown percentage of the population. This means that there are people with no idea they have this sensitivity to visual stimuli–until they are triggered and experience a noticeable seizure. So these people assume the seizure warnings accompanying video games don’t apply to them, or they just ignore them.

Testing tool and methodology

I run downloaded gameplay clips, cinematic clips, and promotional trailers for each game and submit the sequences to an application called the Harding Flash and Pattern Analyzer. (Graham Harding is one of the world’s leading experts on photosensitive epilepsy.) The FPA is widely used by producers and networks in the UK—including by the BBC—to reduce the risk of seizures from material on broadcast TV. I don’t know how many of the major game developers in this country use the FPA–they keep such information very much to themselves.

The analyzer examines video sequences for very specific and measurable image qualities that researchers have found can trigger seizures:

  • rapidly alternating light and dark images (flash/flicker)
  • certain stripes and geometric patterns with high contrast
  • large areas of very bright (“saturated”) red
  • problem images take up more than one quarter of the total screen area

If the first clip I test of a game fails the seizure guidelines test, I then move on to test the next game. If no guideline violations are found, I typically test at least 4 or 5 additional clips of that game–usually more, if I have a hunch due to the game genre and/or overall look of the sequences that there might be unsafe “footage” that I haven’t yet found. Most image sequences that fail the test do so because of strobe-like flicker.

Games that pass could have seizure-provoking sequences that I was unable to locate. I don’t do this testing while actually playing video games. Instead I work with video clips available online, some of which are official marketing and gameplay trailers; others are cutscenes and gameplay sessions posted by reviewers or fans. I avoid testing any clips of gameplay that were made using modifications to the original game software.

Other games I tested in 2015

This year I’ve tested also tested some other highly praised video games for their seizure risk (plus the games recommended by the New York Times and Los Angeles Times as noted above). Those results are here and here.

2 Comments on “CNET endorses 7 video games that can trigger seizures”

  1. Erika says:

    Thank you so much for your research

    • jsolodar says:

      Hi, Erika,

      Thanks for your note. I wanted to test things in time for holiday shopping…but most of the buying guides came out just in the last couple of weeks!


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