Max out all the skills that allow you to level up.
The skills menu can be brought up by selecting Play Game -> Campaign -> Skill Settings from the main menu. Youll also automatically be taken to the Skill Settings menu between chapters.

Purchasing skills requires skill points. Skill points can be earned by killing enemies in Campaign and Mercenaries mode. Larger sums of skill points can be picked up in suitcases/chests throughout campaign. A useful skill to pick up early on is Item Drop Increase. Along with more ammo and healing items, slain enemies will also drop skill points more often.

For this achievement, youre required to max out all the skills that can be leveled up. Any skill that has Lv. next to it is required. It will cost a total of 954,000 skill points to purchase all the skills required.

These are the skills required with their cost per level:


Firearm Lv. 3 | 12,000 | 29,000 | 75,000
Melee Lv. 3 | 10,000 | 25,000 | 75,000
Defense Lv. 3 | 3,200 | 28,000 | 80,000
Lock-On Lv. 2 | 2,800 | 31,000
Rock Steady Lv. 2 | 3,500 | 33,000
Critical Hit Lv. 3 | 3,500 | 13,000 | 32,000
Piercing Lv. 3 | 12,000 | 28,000 | 55,000
Javo Killer Lv. 2 | 3,000 | 25,000
Zombie Hunter Lv. 2 | 3,000 | 25,000
Combat Gauge Boost Lv. 2 | 70,000 | 90,000
Recovery Lv. 2 | 10,000 | 70,000
Field Medic Lv. 2 | 12,000 | 95,000