Sacred Citadel
35 Achievements
500
21-27h
Invincible
Completed all levels without dying.
20
How to unlock the Invincible achievement in Sacred Citadel - Definitive Guide
Rahszhul
TrueAchievements
TrueAchievements
If you keep track of what levels you've died in, you can re-accomplish them when you are at a higher level or have better gear and they will then count as completed towards this achievement.
An easy way to track what levels you've completed is if you complete the Life challenge for each stage. Once completed, the heartbeat icon will be lit up in the stage select menu.
Edit: Thanks to Choskie for the following comment.
I can confirm it counts across different classes; my co-op partner earned the achievement on our second run of the game using a new character. :)
eeysi
TrueAchievements
TrueAchievements
Make sure, you go into town before playing the act.
Go see "The BET guy" and bet on Life Challenge !
Tyger7
The only way to track this is by completing the challenges associated with not dying. To accept these challenges you have to highlight the level you are going to play and press 
to go into down. Talk to the bookkeeper and create the challenge to beat the level without dying. Now play and once you complete the level without a death, the challenge icon will be lit up. You don't have to do the challenges to get the achievement, but it is the easiest way to track it. This does not have to be one with one character, you just have to have beaten ever level once without dying no matter who you chose to be.
Takuru
stratege.ru
stratege.ru
