Stamina, along with Charisma, is one of the two basic stats unique to the player. It is a resource consumed by a large number of Missions. Being much rarer than Charisma, it is also far more valuable, and should not be wasted.
Players begin the game with 12 maximum stamina. This maximum increases by 1 at Rank 101,120,140,160,180 and 200, to a maximum of 18. When one of these levels are reached, players also fully recover their stamina.
In normal time, it recovers at a rate of 1 point every hour. Players can also instantly recover all of their Stamina by using 1 Sacred Crystal at the Shrine. In doing so, players retain any excess, though regen will be disabled until it is spent.
After reaching Rank 200, subsequent rank-ups will fully recover both Charisma and Stamina. A newly added feature specific to DMM Aigis only allows the player to retain excess Charisma and/or Stamina upon levelling up, which is convenient as the player no longer has to use up all of their Charisma and/or Stamina before levelling up.