Im going to use my concept for perks for this. Anyways come up with perks (not OP) that could be in the game. Tips:
Each player would have a balance of 15 points to spend on perks, so choose how much each on is wisely.
Perks can be in multiple levels, and make sure the first one is a little more expensive than the others.
Scout (Level 1) - 3 points
+X% Run Speed
+X% Quietness
Scout (Level 2) - 1 Point
+X% Run Speed
+X% Quietness
Scout (Level 3) - 1 Point
+X% Run Speed
+X% Quietness
CQB (Level 1) - 3 Points
+X% Melee damage
Melee degradation extremely minimized
CQB (Level 2) - 1 Point
+X% Melee damage
CQB (Level 3) - 2 Points
+X% Melee damage
Silent when attacking enemies with melee weapon.
Weightlifter - 2 Points
Weight has less affect on movement speed.
Conditioned - 2 Points
+X% run speed
Gun Smith - 3 Points
With some scrap metal, you can fix any weapon.
Guns degrade slower
Mechanic - 3 Points
Be able to drive, fix, and upgrade all vehicles.
Scavenger (Level 1) - 2 Points
Better chance of finding rarer items.
Ammo has X% more.
Scavenger (Level 2) - 2 Points
Food and ammo become easily found (Outline of either will appear through walls)
Berserk - 2 Points
When Health drops below X%, player gets a X% boost to speed, stamina, and melee damage for X seconds.
Leadership Qualities - 3 Points
Teammates within X Radius gain X bonus to Health, Health Regen, and Accuracy.
Adrenalin Rush - 3 Points
Killing X enemies will result in a X% damage/speed/stamina regeneration boost for X seconds. While in effect, every enemy killed adds 1 Second (2 if using melee weapon).
Negative perksYou can have up to 2 of these active at a time, and they give extra points to use.
Fear of Heights - +2 Points
When 2 stories above ground level, become louder, accuracy drops, and all actions are slower.
Can't ride in aerial vehicles.