In slacklining, you balance your way across a flat rope, similar to tightrope walking. Yet the difference is in the type of rope and its tautness, which altogether can feel more like a really thin trampoline. It's a fun reason to try something new with family and friends and is a surprising way to destress, too.
At first glance, it looks intimidating as hell because slacklining demands an insane amount of balance, but it's about committing to it. The rope will sway like crazy and make you think twice, but it will hold if you set it up right. If the current tension makes you uncomfortable, you can adjust it to add more or less of it for your skill level, and use hiking sticks or someone as support initially. My favourite part is that when you slackline, you're completely and utterly present in the moment, almost like a zen state. No thoughts about work, bills, or what to eat for dinner.
The slackline itself is made from flat nylon webbing that's about one to two inches in width. Ideally, you set it up outside between two very sturdy anchor points, like trees (but remember to include some sort of padding to avoid damaging them.) This video by Absolute Slacklines shows that you can set one up indoors. Just make sure the anchor points are super secure. If you don't want to buy a slackline, this tutorial teaches you how to make your own.
For more, the slackline subreddit is a helpful deep-dive into the world of slacklining.
Slackline: Setup, Basics, Tricks and Why You NEED One [Human Machines]