All it took for me to get access to adult games was clicking a button in my profile: no age verification or anything. I am an adult, and currently only have sfw content on my itch, but I want to expand my horizons and publish some nsfw zines. However, I cannot earnestly do that on this account where underage folks could /say/ theyre adults and get access to them. There needs to be an age verification feature, with punishment if you lie about your age. There also needs to be an option for creators to mark their entire accounts as 18+ (kinda related to this, it would be nice if we could have two itch accounts under one email so I could use a sfw and nsfw account concurrently, so you dont have to go through the hassle of managing two payouts). NSFW artists can get in serious legal trouble if minors get ahold of their work, please consider doing something about this

I don’t think something like this is technically possible. Unless you have a policeman on entry checking their documents. If they can click “I’m 18+”, they can lie about anything. It’s their problem, not yours.

Most of “more than that” (e.g. forcing to bind account to a credit card, provide a verified documents photo, link to social media account) usually will harm valid users more than make the life a bit harder for liars/cheaters.

The only thing that can (and should) be done is to keep the cover art PG-13 as it may display along with other search results or in your profile.

I love the way Itch.io allows downloading games even to non-logged in users and not imposing dozens of limitations and privacy breaches on logged in ones, and I’d really like it to stay that way.

The only real way of doing this would be to get people to email photo ID and this creates more problems than it solves- a lot of work for itchio, serious issues in the event of a data breach, and anyone who's ever used Photoshop could get past it easily.

Internet companies can't really enforce punishments in the event that someone lies about their age, and each country's laws differ so that throws up even more issues.

One possible idea would be to have an opt-in button for 18+ content and default to not showing NSFW games. It's no inconvenience or real barrier, but it would at least stop children (and adults) who don't want to see these things having to while browsing.

Because kids have never lied about their age on the internet.

And if Itch started requiring age verification like through ID, credit card, etc.... well, no. That's pretty horrible, not to mention extremely resource intensive for itch themselves. The internet is what it is. If kids are accessing adult content then that's on the parents/guardians for not implementing proper parental control over their children's devices. Website admins are not a substitute for good parenting. There's an opt-in that must be enabled to see NSFW content, that's as far as itch really needs to go.

NSFW artists can get in serious legal trouble if minors get ahold of their work

Uh. No. Unless it's a law in some authoritarian nation, then no. This isn't even remotely true for the majority of the world.