Achievements are awarded for many things on Royal Road. Some are automatic, like the review upvotes and top list achievements, others are rewarded for participating in one-time events, and some are given manually, such as the art achievement.
On special occasions, it is possible that one-off unique achievements get given out. An example would be the achievement given to the first person that reached the maximum level on Royal Road.
The achievements currently obtainable by your account on Royal Road are shown on the Achievement Management Page. Further achievement paths are opened up as more actions that provide achievements are started. Author achievements are not visible to users without any fictions, for example.
Achievements give experience in relation to the difficulty or rarity. The achievement for reaching the top 10 best rated gives more than the one for the top 500, as an example.
Apart from the
experience they can also be showcased in a couple of places on Royal Road. The first
places are on your fiction. Up to 15 achievements are shown under the About the
Author section on these pages.
It can also be seen under your username in the forum. They can also be seen in more detail on your profile page.
If you have more than 15 achievements, not all will be shown in selected places, except for the profile page. In order to manage what achievements you want to have shown, you can go to the Manage Achievements page.
If you reached the expected number to get an achievement, but haven't received it yet, please wait until midnight GMT.
If you believe you qualify to receive the Art achievement, which is manually given, follow the steps listed here https://www.royalroad.com/forums/thread/112569