Completionist

Complete all quests.

75

Although the achievement specifies that you must complete all quests to unlock it, in reality you only need to complete 80. This is due to the fact that many quests can easily be missed if you progress too far in the main story or if you fail to complete them within a specific time frame. You can therefore choose to complete any 80 quests of your choice, but be sure not to complete the main quest ‘The Die is Cast’ before you have completed all available side quests, as many will become available after this point.