How can I check the total played time of a character?
Solution 1:
To find out how long you've played a certain character, when you're on the character selection screen, select a given character. It says on the right how long you've played them:
You can also find out how long you've played a class. When you're on the screen just after the character selection screen (the one from which you start a game, change quest, etc), press P to bring up your profile.
You'll see a screen that looks like this:
Hover over the class to bring up a tooltip for how long you've played it.