Every merc in Zombie Assault: Resurgence has 12 skills: 6 Core skills that anyone can take and 6 Class skills that belong to that class only. They are bought with two separate currencies — Core Skill Points and Class Skill Points — which cannot be spent on each other's skills, and both are handed out when the merc levels up. A skill takes up to five points, and the fifth point does not add a bigger number: it unlocks a capstone that changes how the skill works.
Core skills and class skills
Core skills are shared by all three classes, so a Fast Movement investment is the same on Assault, Heavy and Medic. Class skills are unique to the character class, which is why the same skill can cost a Class Skill Point on one merc and a Core Skill Point on another: upgrading Adrenaline on an Assault costs a Class Skill Point, while upgrading a Core skill such as Fast Movement costs Core Skill Points.
The two systems sit next to each other but stay separate. Your skill tree builds passive stats, while your three activated abilities unlock on their own at set character levels and are upgraded with a different currency entirely — the activated abilities page covers that side of the build.
How a skill grows: five points and a capstone
Each skill uses a sliding progression instead of a flat per-point increase. The first point gives a clearly noticeable improvement, the following points build on it, and the fifth and final point unlocks a completely new capstone effect rather than another numeric bump. Three published capstones show how different they can be:
- Fast Movement still reaches its maximum 20% movement speed increase, but it does so after four points. The fifth point unlocks Sprint, where moving continuously in one direction without firing builds up a much faster sprint.
- Hardy gives you a protective shield at the start of every deployment once the skill is maxed.
- Fitness heals you a small amount the first time you are reduced to zero health in a deployment, giving you a second chance in the same mission.
The three launch skills: Powerful Build, Battle Ready, Payday
Three Core Skills were retired at launch because they duplicated stats that weapons, armor and mods already provide: Fast Reload, Critical Shot and Resistance, the last of which also overlapped with Hardy. They were replaced with three new ones.
- Powerful Build reduces the movement penalty from carrying heavier equipment such as Power Weapons or mission objectives, and its capstone lets you carry more turrets and grenades into a mission. That penalty is the constraint behind every loadout decision, so it is worth taking early, and the loadout page shows where it bites.
- Battle Ready is a universal cooldown-reduction skill that everyone can invest in, and its capstone lets kills reduce your ability cooldowns. Do not confuse it with the Adrenaline upgrade of the same name.
- Payday gives zombies a chance to drop Creds, and its capstone adds crafting materials such as Alloy and Manufacturer Parts to the drop pool while raising the Cred payout at the end of a mission.
How many points you get, and when to respec
The total number of skill points available was increased for launch, but it is deliberately not enough to unlock everything, so where you spend them matters. You are not locked in either: skills can be re-specced at any time for an in-game currency cost, so a build can be changed without starting over.
Levels are the other half of that budget, since points arrive when the merc levels up and abilities unlock at set character levels. The published level numbers and what each level opens up are in the max level page.