Linux

I tried wget and got a small index file that looks like a bot challenge, maybe Cloudflare Turnstile. I don't know of a simple automated workaround. But, Turnstile gives you a rewritten url that then goes back to the forum page and sets a cookie, iirc. So if you can visit the page with a real browser, then save the cookie and transfer it to wget (there's some option to set an arbitrary header) that's one thing to try.

There's another hack used by fanfiction.net readers, where if you want to save a multi-page story, you can manually visit each page with a browser, i.e. click "next" again and again to load all the pages. Up to a few dozen such clicks isn't so bad. Fanficfare (fanfic downloading program, sometimes abbreviated FFF, https://github.com/JimmXinu/FanFicFare ) then has an option to retrieve the pages from your on-disk browser cache instead of trying to get them from the remote server. That's another approach you can try, either with fanficfare or your own scripts.

The site you're looking at uses xenforo which is a very popular forum server program. The actual layout of xenforo sites varies, but fanficfare probably already recognizes something similar, so try using one of those interfaces. I think spacebattles.net (another fic site) uses xenforo and FFF supports it, so it might be a good start. You will have to modify FFF to recognize civfanatics instead of spacebattles. It will help to know or pick up some Python, but you shouldn't have to become an expert.

Added: if you really want to automate your scrape, you will have to orchestrate a browser as mentioned earlier. IDK if there is code around to already do it. If you can program, it's not terribly hard to use Puppeteer or Selenium, but it will take some farting around to deal with the site layout and anti-bot stuff. It's not guaranteed to work right off the bat, but with enough determination you can do it, especially if your scrape volume is low and you can run it slowly. I'm not deeply involved in this stuff (like you, I just occasionally want to download something for personal use) but there are tons of webpages and articles by people (who I'd mostly consider evil) who do it at scale.

Many websites are detecting tools like curl, wget and httrack and either rate limit or block them. Sometimes one can get around it when using more detailed configurations that mimick like a human using a real browser, but that is basically tricking them. The reason why they are blocking such automated tools is multifolded (if that is even a word): a) downloading pages and data in short amount of time creates huge stress for the servers, meaning its like an attack that halts their systems, b) that in turn also leads to higher server costs for them, c) they don't get visitors for the advertisements and engagement, as the tools download autonomously, d) is also sometimes seen as theft from Ai companies, so they do try to block automated mass downloads.

Besides these tools there are other ways, more sophisticated and requires more work to mimick real browsers. In some cases even using real browser engines, but changed the browser in a way to make automated work possible, such as https://www.selenium.dev/ . Especially needed when JavaScript and other dynamic content is involved. Maybe even programming Python with custom solutions. There is also a way to directly program in Typescript using https://deno.com/ . But these solutions are a bit advanced and only recommended if you want go deeper.

Soo, having all said that, this might not help directly solving your issue, but I hope its still helpful in why its difficult. Especially nowadays, because companies have better detection and blocking, because of Ai...