Stamina is used during all types of Battles. At higher levels for certain types of battles, you will be given the option to use more stamina to Boost your attack strength. Stamina refills with time. For quick refills of Stamina see The Gods. Increase your maximum Stamina with Skill Points from your Profile. Each time you level up you will receive bonus stamina up to a maximum of 50 or your characters max whichever is less. Like i said just another way Kano makes money off the game!!