What is stamina?
Every player starts with 56 hours stamina. Only when you fight monsters, time is deducted from your stamina. When you chat or simply walk around, no time is deducted.
Gaining XP with different stamina:
56-54 hours -> +50% XP
53-15 hours -> normal XP
14-00 hours -> 50% XP
00 hours -> no XP at all
Stamina regenerates while characters are logged out. For every 2 minutes you are offline (not logged into the game), your character will regain 1 minute of stamina. So you need to rest 2 hours to regain 1 hour of stamina. Please note, however, that stamina only starts to regenerate after you have been logged off for 10 minutes.
In the "Info" menu of your client you will find the menu point "Character info.", Inside it find "Stamina" which shows you your current remaining stamina time. Shortcuts (# 1 4)
If you new player, check this list: