Why this topic at all
I make games in my spare time, just for fun. Most of them are full of lights: lamps and lasers in the bar, a buzzing tube light in the workshop, sparks at the forge in the fortress, confetti in the arena. Light is great fun, but there is one thing I must never forget.
For some people, very fast flickering light can affect the body badly. We call them people who are sensitive to light. One form of this sensitivity is photosensitive epilepsy. That is a hard term, so in plain words: for someone who has it, rapidly flashing images can trigger a seizure. Not everybody has it, and many people never find out they do. But I cannot see who is sitting on the other side of the screen, so I prefer to assume it might be someone like that.
That is why I wrote down a rule at the very start of the series, and I keep to it in every new game.
The rule: at most 2–3 flashes per second
I keep it in the notes I use for every game, in one sentence: strobes at most 2–3 per second, short bursts, an off switch in the settings.
Let me split that into three parts.
- At most 2–3 flashes per second. This is the upper limit I never cross. A flash is a sudden brightening or darkening of a large part of the screen. When something in a game is supposed to flash, I count how many times that can happen in one second and I do not allow more.
- Short bursts. Even those few flashes must not go on forever. An effect starts and ends quickly. For example, the flickering tube light on a title screen dims at most once every few seconds, not all the time.
- An off switch in the settings. Anything that can flash can be turned off. Nobody has to explain themselves or look for workarounds.
The same rule applies to my material outside the games. I prepare trailers and cover images the same way: one smooth camera move, no sudden flashes, at most 2–3 per second.
A storm without flickering
Weather is a good example. A storm in a game practically begs for sharp, white lightning flashes. I did the opposite. The shared sky code that my games use describes lightning as soft, rare brightenings. The light rises and fades slowly, over roughly a second, and the brightening is capped so the sky never turns into a white wall. Harsh strobe-like flashes are ruled out. Reflections on water and night lights change slowly. Thunder rolls in a moment after the brightening, like in a real storm, so the storm still has its atmosphere.
Combat works the same way. In My Fortress, battle effects are a puff of dust, flying cabbages, bubbles, sparks at the forge and planks when a building falls apart. In the game plan I wrote it plainly: no flashes above the limit. In My Arena a disco ball bounces enemy shots back, and I noted that it does so without flashes.
Where to find the switch
The switch lives in the game settings. Open the ☰ menu and choose settings. The option names differ a little between games, so here are the real ones.
- My Bar and My Garage: the option "Strobe and light flashes". Its hint says: turn off if flashing light bothers you. When it is on, the game shows at most 2 soft flashes per second, in short bursts.
- My Fortress: the option "Safe flashes". When it is on (the default), flashes in battle are soft, at most 2 per second and in short bursts. When it is off you get fuller effects, but the limit still applies: never more than 3 flashes per second. I did that on purpose, so even "full effects" never go past my line.
- My Arena: the option "Confetti and clouds". This game has no flashes, but confetti and "poof!" clouds can add a lot of movement, so you can switch them off. Next to it is "Reduced motion", which calms the scene: less swaying, fewer menu animations and effects.
The other games (warehouse, school, cemetery, hospital, stables) have no separate flash switch. I still apply the rule of at most 2–3 flashes per second there too. If I ever add an effect that could flash, it will get its own switch.
One important note: these settings are stored in the browser, on the device you play on. If you play on a second phone or computer, check the settings there as well.
What I do not promise
I am not a doctor and I will not pretend to be one. I give no medical advice here and I do not claim that my games are safe for everyone. I only say what I actually do: I use my own cautious limit, I keep effects short and I give you an off switch. This lowers the risk but does not remove it, because different people react differently.
If someone in your family is sensitive to light, the details are best discussed with a doctor. All I can do is make sure the game does not make life harder.
What to do if something feels wrong
A simple rule that works in every game:
- If you feel unwell while playing, feel dizzy, your eyes sting or your head hurts, stop playing. Step away from the screen, rest and drink some water.
- If it is a child, they should tell a grown-up. The grown-up should stay calm and look after the child.
- The game will not mind and you lose nothing. Progress is saved automatically, so you can come back whenever you like.
- When you play for a long time, take breaks.
If something in a game worries you, let me know. I would rather hear about a problem and fix it than never find out.
Why I do it my way
I could put sharp flashes into a game because they look spectacular in screenshots. But a game should be for anyone who wants to play it: a child, a parent, a grandma. To me it matters more that everybody can play in peace than that one explosion is slightly brighter.
A well-designed effect does not need flashes to impress. A puff of dust, a slowly rising glow or a flying cabbage work just as well, and they hurt nobody. That is my answer to the question in the title: safe flashes are the ones that are few, short and can be switched off.