Unit capacity is an upper limit of units that the player can possess.
The initial value starts at 58 units and can be increased in a number of ways to a maximum of 240 units.
- Players can buy box extensions in the shop and get 4 permanent extra capacity for the price of 1 Sacred Crystal. This can be done up to 35 times for a total of 140 capacity.
- Every time the player increases their rank to a multiple of 10 (e.g. 10, 20, 30), 1 extra unit space is given. In total the player receives 20 extra unit capacity from this method.
- Completing certain numbers of Challenge Quests (multiples of five but not ten; i.e. 5, 15, 25, 35, 45) will gain the player an additional 2 unit capacity on each milestone up to 10 in total.
- Completing certain Story Missions (Citadel Battle, Castle Retake and Base Scramble II) earns the player an additional 4 unit capacity the first time each mission is completed up to 12 extra unit capacity.
As of 10/06/2015 it is also possible to buy additional space in a form of 2nd and 3rd barracks. Players can purchase these barracks for 30 Sacred Crystals each, although they are only available after purchasing all 35 Box Expansions and attaining Rank level 25.