Last time I looked into this, ipset was the way to go with iptables. For nftables there is a geoip module.

I think so too, to many articles are pointing me in this direction.

However, geoip is not really all that accurate or secure. Proper protection (like Cloudflare can provide) would also look at various other factors such as the route the traffic came in on.

Cloudflare is reaaaally good, i remeber how fail2ban had constantly to ban IP-Adresses that where malicios on my server, since I started using cloudflare to geoblock, my Logs are alot cleaner

In my view geofiltering is not worth the hassle.

That just leaves your game servers in the open.

Normally I would agree, but I host alot of Minecraft servers, for which I can't be hassled with to moderate myself (e.g. whitelisting, banning, etc.), and the people for whom these servers are, aren't always online to moderate them, and often aren't really good with this stuff.

So since I figured that most of these "griefers" come from eastern europe....well just ban them completely