As you play Errant and interact with the world, you may earn multiple forum achievements. There are several categories of achievements, and some achievements can be earned by multiple members. Rarer, more prestigious achievements will only be earned by one member.
Achievements will appear as icons added to your member tag list. They each have unique icons. Players who earn the achievement will also be listed by that achievement's name, and an announcement will be made regarding a player earning a new achievement.
Note that these are just a few examples - there are many hidden achievements, not all of which are listed, and many that will be made in the future as events occur!
Death and Dice Rolls:
Council of Magi:
The Iron Gauntlet:
Army of Chaos:
Empire of Rognosst: