If you are looking for more wargames like this, https://www.wechall.net/ has a large index and allows you to keep a persistent score based on which challenges you have completed.

OverTheWire has some really fun wargames. I made it through Bandit and Leviathan not too long ago, and I only have one more challenge in Natas. They do a good job on the difficulty overall, not too difficult to start, but it ramps up pretty steadily, giving you a chance to learn. I'll have to get back on this over the weekend.

Quite a few of these wargames has an interesting history. I think at least Leviathan, Narnia, Behemoth, Utumno and Maze originates from a site I believe had the url wargames.net about 15 years ago. That site got transformed into dievo.org (Digital Evolution) which later closed. intruded.net picked up the wargames to keep them online and they then ended up on overthewire.org.

I have very fond memories of hanging around the wargames.net and later dievo.org irc-channels in my late teens talking to the wonderful and talented people there (lots of swedes if I remember correctly). While the late night talks might have messed with my school grades somewhat I'm pretty sure I learned more from those people than I learned from school anyway. :) I probably wouldn't work as a developer today if it weren't for those communities so a big shoutout from Woodman if any of you are reading this! :)

I had a lot of fun on this site. IIRC this is where I first learnt to exploit a buffer overflow.

This is awesome stuff. I've blown through the majority of the Bandit levels pretty quickly but looking at the other games it seems they easily go way beyond my skill level. Easy to get started and keep going through the levels since it's all ssh. Would highly recommend anyone thinking about it checks this out.

These are amazing.. finished a bunch over a night out. Although I feel they might have to prepare for the HN/slashdot effect... Lots of people might be trying to ssh. :D

It did start to feel rather sluggish a few minutes ago...

Don't know whether that was my computer, my Internet connection or their servers groaning under the load ;-)

What a surprise, it only works in Chrome... More specifically, in FF the menu on the left is missing, Wwich at first I though may have been a first challenge...

Oops, a fresh ff install fixes it. Sorry.

I did these years and years ago when it was called something else, but I can't seem to remember the name.

You might have seen some of them on wargames.net, dievo.org or intruded.net (in chronological order) where some of them have been hosted before. :)

Pull The Plug.

Yes! That's the one. Thank you.

Pulltheplug

I keep reading this as "Wargmans", like the war-mongering version of Wegmans or something.

Nice idea and progression of difficulty. I second this as very good and smooth intro.

Wow this is awesome!