about 4 years ago - Tynan - Direct link
Like a few others mentioned, the only mod content integrated any time recently was animals art in the 1.1 free update, provided by Oskar Potocki. We also hired him to do art for Royalty. And of course he's in the credits and was thanked in both the 1.1 and Royalty announcements.

Royalty is 100% original and created by us.

Of course there are some passing resemblances to some existing mods, but it's nearly impossible for this not to happen. There are 5,000+ mods for RimWorld, and there are only so many natural and obvious ways to expand the game. So modders have been anticipating things we were going to do for years now, back into the alpha days.

In some cases they actually came after us, it's just that we've been developing Royalty in secret for 16 months so we released later. (e.g. Psychic Awakening mod has a surface similarity to Royalty's psychic powers; it was released in November while we internally implemented psychics around summer.) And in each case the similarity is superficial, the actual design and implementation and play experience are very different.

We would never just take a bunch of mod content and start selling it as a DLC, especially without crediting the authors. I hope our track record over the last 6+ years can give people some confidence on this front.