u/Ikantfindaname

As a long-time Terraria fan, but rather inexperienced builder, I'm trying to understand some of the more complex parts of building. I've got the basics down, but I find it hard detailing rooms very uniquely, and while browsing this subreddit for inspiration, I noticed a lot of people talking about actuators. I was wondering what they did and how they worked, cause the in-game description is rather confusing. Can anyone explain them to me, and maybe some examples of what they're used for? Any other building tips, especially with wiring or painting, would be welcome as well. Thanks a lot!!