Intelligence is a support stat used to help enhance the players growth. It is a core stat which impacts many other systems.
Intelligence directly impacts the number of BattleStats gained from the Gym. There is a significant difference between training a BattleStat with no Intelligence when compared to maximum Intelligence.
Intelligence also improves success chances on Jobs and also acts as a prerequisite to completing some jobs, as without the required INT the more difficult Jobs are often impossible or exceedingly difficult to complete successfully.
The Intelligence stat can be increased through the University by spending Energy "Studying" to increase the stat similar to how BattleStats are trained.
Intelligence can also be increased by completing many of the University Courses.
Intelligence currently has an natural upper limit of 1,000 INT after which additional Intelligence cannot be without perks from properites. Once this point is reached the ability to Study is disabled in the University, and it instead shows a message stating "Cannot Study further, reached max Intelligence from Study".
In order to increase Intelligence artificially a property should be built which has the library perk and has to be bought. Each property has a library perk limit and each level can artificially increase the player's Intelligence limit.
Level 1 - 50 INT
Level 2 - 100 INT
Level 3 - 150 INT
Level 4 - 200 INT
After purchasing the perk the player must spend energy in order to gain the newly obtainable Intelligence.