If you complete certain tasks or milestones in the game, you'll permanently receive five bonus points per achievement on each of your five attributes. For example, you have to reach a certain level, find mushrooms, be actively involved in a guild, collect and carry an item set, and much more.
You can find out what achievements you can reach in the Scrapbook. There you can also see which achievements you have already unlocked and how the progress of unfinished achievements is if they depend on a certain progress.
Notes on certain achievements
Activity achievements such as "Always on" require a daily login to the game. Intermittent logouts are required to unlock the achievement. Otherwise the progress of the Achievement will reset. No more than 24 hours may elapse between logins to preserve progress for this achievement.
The achievement "Reliable" (be actively involved in a guild for 10 days) only counts if you get ready for an attack or defense, but you did not start the attack.