 Hey there Foundation staff, Sherm here, and welcome to Sherm's Declassified Skip Survival Guide. Today we are going to try and sort out the different types of K-class scenarios in Foundation lore. It's important to remember that because of the Foundation's flexible canon, this is not at all a perfect list, but it is a great springboard for understanding different kinds of K-classes that you can use for your own skips. This list is 90% drawn from an extensive list created by user TheDeadlyMoose back in 2012. In the interest of brevity, I'm skipping the lesser used versions and the great list of examples that TheDeadlyMoose provided. Check out the source link below if you want to dive deeper. An important starting point for our list is the granddaddy of them all, the XK-class. It originally stood for an Abrahamic religious apocalypse, but was not called as such because the Foundation is sterile in its classifications. Since then, it has evolved to stand for All Life on Earth is Destroyed and won't be coming back anytime soon. It's also used as shorthand for End of the World, so sometimes you'll see an XK-class even when it could be classified as one of the following scenarios. From there, let's get alphabetical. AK-class End of the World The world undergoes a restructuring of subjective reality, otherwise known as Everyone Goes Crazy. Such things alter everyone's view of reality or spread mimetically and cause everyone to spread it until all are infected. CK-class Restructuring Reality is altered to a new normal, sometimes due to changes in the past, fricking time travel, sometimes due to a reality bender, sometimes due to natural laws like gravity up and changing how they function. GH-class Dead Greenhouse Near extinction of life on Earth, but upside, it's a scenario we can and have come back from before. NK-class End of the World The original definition was an explosive event with effects on a geological scale, but that was deemed a little bit too specific and the meaning has morphed into the grey goo scenario. An End of the World via self-replicating skip such as too much self-replicating ink or too many self-replicating cakes. RK-class Restructuring Outcompetition of standard Earth species by non-standard species such as extraterrestrial or extra-dimensional entities. Very similar to our following, SK-class Dominance Shift. When humans are replaced as the world's dominant life form by another life form or an alternate form of humanity. ZK-class End of Reality The Ultimate Destroys A-reality or even every reality depending on the situation. Remember, these are the most used K-classes. You'll find other lesser used ones now and then, and you'll see these ones used in a completely different fashion than I've presented here. That's perfectly fine because that's the way the Foundation's flexible canon works. Take this list as a guideline rather than a hard rule. Thank you guys for tuning in to another episode of Sherm's Declassified Skip Survival Guide. If you like what we're doing on the channel, do that like, share, and subscribe Mumbo Jumbo, and don't forget to click the bell. And if you really like what's going on around here, hit up the Site 42 Patreon or the Site 42 Store and support the channel that way. You can also join the Site 42 Discord server if you want to venture deeper into Site 42 itself. See you next time, Foundation staff.