The Strength stat affects a survivor's raw physical prowess, allowing them to delivering strong blows with melee and unarmed attacks, and carry heavy weight, and more weight overall. Melee specialists should have high strength for maximum effectiveness.
The Perception stat affects a survivor's awareness, and notice things that may be hard to see such as hidden traps and targets, as well as hear enemies such as bandits and walkers from a greater distance. Guns or Stealth specialists should have high perception for maximum effectiveness.
The Endurance stat affects how much pain, damage, and disease a survivor can resist, as well as effects a survivor's stamina. Combat focused specialists should have high endurance for maximum effectiveness.
The Charisma stat affects a survivor's leadership and how others trust you, lower numbered charisma could result in a survivor having a bad reputation, and survivors leaving a group. Leaders should have high charisma for maximum effectiveness.
The Intelligence stat affects a survivor's strategies and planning, as well as a survivor's reputation and respectability. Medicine and Engineering specialists should have a high intelligence for maximum effectiveness.
The Agility stat affects a survivor's speed and movement, as well as stealth. Stealth specialists should have a high agility for maximum effectiveness.
The Luck stat affects how close supply drops are to survivors, how survivors survive close encounters such as wounds and close zombie encounters, as well as how much loot a survivor gets from scavenging and raids.