Chapter 1
Agility in Build 42
4 skills decide how fast you move and how much noise you make doing it. Together they are the difference between being chased and being ignored.
Running
Was called Sprinting. Faster running, less stamina drain.
Lightfooted
Quieter footsteps in every kind of movement.
Nimble
Faster movement in combat stance. Quieter feet too.
Sneaking
Harder to spot while crouched. Quieter crouch steps.
The ghost's loop
- CrouchNear zombies, unseen.
- MoveEvery step near them is XP.
- Combat stanceWalk it around base for Nimble.
- RunOn safe roads for Running.
- EscapeBecause you can.
Why it matters
Combat skills win fights. Agility skills mean you choose which fights to have.
Chapter 2
Build your runner
Agility levels come from jobs and traits, and from the sneaking you do anyway.
Fitness Instructor (job)
Running and Fitness. Built to move.
Burglar (job)
Sneaking, Lightfooted and Nimble. The stealth job.
Park Ranger (job)
Sneaking among outdoor skills.
Gymnast (trait)
+1 Lightfooted and +1 Nimble.
Hunter (trait)
+1 Sneaking among others.
Runner, Graceful, Inconspicuous (traits)
Runner gives Running. Graceful cuts footstep volume to 60%. Inconspicuous makes you harder to spot.
Watch out: point costs change
The game makers still tune traits and jobs. Always read the numbers on your own character screen.
Secret: a starting point levels 4 times faster
The official wiki says a skill with 1 point at creation levels much faster than one at 0. Running has its own gain table: 100%, 125%, 133%, 166% for 0 to 3 starting points. One point in your main agility skill is a huge deal.
The Grady v King VHS gives Lightfooted XP. Agility skills have no skill books.
Chapter 3
How zombies notice you
2 senses. Sight first, then sound.
- Sight. Line of sight is the main way zombies find you. Low fences and parked cars block it while you crouch. Weather shrinks how far they see.
- Sound. Your footsteps have a radius. Zombies in it have about a 50% chance to hear each step when you are not sneaking. Sandbox: Hearing Indoors, the radius is halved.
- Fights, doors, cars and guns are far louder than any footstep. Stealth does not cancel them.
Secret: 4 sandbox dials
Hearing, Sight, Follow Sound Distance and the day and night speed option all change how this plays. Check your server before planning a stealth grind.
Chapter 4
Running
The old Sprinting skill. Faster, longer, cheaper running.
- Each level raises run and sprint speed and lowers the stamina cost.
- XP comes at random intervals while running or sprinting, split evenly with Fitness.
- Only moving counts. Running into a wall does nothing.
Secret: run the loot route
Jog every safe road between houses instead of walking. Never sprint with no stamina reserve near danger.
Chapter 5
Lightfooted
Quieter footsteps, no matter how you move.
- Lowers footstep noise while walking, running and crouching. The level factor goes from about 0.99 down to about 0.20 at 10.
- Also boosts Sneaking, making zombies more likely to ignore your steps entirely.
- XP comes from moving near zombies without being detected. More zombies nearby means more XP.
Secret: alarm clocks make a classroom
Set an alarm clock to pull a crowd. Crouch-walk around the edge of the group. XP scales with how many are near. It is the official wiki's own suggestion.
Watch out: barefoot halves the radius
Taking your shoes off halves your footstep sound. It also lodges glass in your feet. Do it only on clean floors.
Chapter 6
Nimble
The combat safety skill. Faster in combat stance, quieter everywhere.
- Combat stance is holding the aim key (Left Ctrl or right mouse) with a weapon.
- Higher Nimble means faster movement in that stance. Backpedaling from a group becomes safe.
- Its footstep reduction goes from ×1.0 to ×0.5, and it applies to all movement, stacking with Lightfooted.
- XP: walk in combat stance while actually changing position. No zombies needed.
Secret: hold aim while walking around base
Every chore trip in combat stance is Nimble XP. Slow, but free and safe.
Chapter 7
Sneaking
Being seen less while crouched, and quieter crouch steps.
- Lowers the chance zombies spot you while sneaking.
- Its crouch noise factor goes from about 1.14 at level 0 to about 0.48 at 10.
- XP: sneak near zombies while unseen. Zombies already chasing you give much less.
Watch out: crouching in a corner is not XP
Concealment is not training. You must be moving, near zombies, unseen.
Chapter 8
The noise stack
Footstep noise is a chain of multipliers. Every skill and trait stacks.
| Factor | Effect on crouch-walk volume |
|---|---|
| Graceful trait | ×0.6 |
| Sneaking level | ×1.14 at 0, down to ×0.48 at 10 |
| Lightfooted level | ×0.99 at 0, down to ×0.20 at 10 |
| Nimble level | ×1.0 at 0, down to ×0.5 at 10 |
| Indoors | Radius halved |
| Barefoot | Radius halved |
Everything maxed, crouch steps are about 99% quieter than base. Zombies still see. A door, a fight or a car engine still gives you away.
Chapter 9
Combat stance: the safety skill
Why Nimble is rated one of the best survival skills.
- In a fight, you back up while swinging.
- Low Nimble: you shuffle. The group closes.
- High Nimble: you glide. The group never reaches you.
Watch out: combat stance is louder
Raised weapons increase noise and visibility compared to a passive crouch. Use stance to fight, not to sneak.
Chapter 10
Crossing open ground
Practical stealth. Skills help. Routes matter more.
- Crouch along the shadow side of low fences and parked cars.
- Use fog and rain to cross streets. They cut sight range, not hearing.
- Keep a stamina reserve. Crouching costs more than walking. An exhausted crouch-run gets you spotted when you stop.
- When the helicopter comes, get indoors and stop everything loud.
Chapter 11
Traits that change everything
| Trait | Effect |
|---|---|
| Graceful | Footstep volume ×0.6 |
| Inconspicuous | Harder to spot |
| Clumsy and Conspicuous | The opposites. Cheap points, real cost. |
| Runner | Starting Running level |
| Gymnast | +1 Lightfooted and Nimble |
| Hunter | +1 Sneaking and more |
Chapter 12
Training plan: 0 to 10
No books. Movement is the grind. Make it a habit, not a session.
Every day: the 3 habits
Crouch when zombies are near. Hold combat stance walking around base. Jog safe roads. That trains all 4 without a plan.
The alarm clock class
For Lightfooted and Sneaking: pull a crowd with an alarm clock or a shout from a safe spot, then crouch-walk around the edge unseen. Have a car and an exit.
Levels 6 to 10
Same habits, more months. A starting point in your main skill and the Gymnast or Runner trait cut the time a lot.
Watch out: sirens
Some players use a police car siren to pull a huge horde for XP. It can end a run. Only with fuel, a route and a willingness to leave the car behind.
Level by level: Sneaking, Lightfooted, Nimble, Running
The best single thing to do at each level. Read the matching book first when one exists.
| Level | Do this for most of your XP | Why |
|---|---|---|
| 0 to 1 | Crouch near zombies, unseen, moving. Watch Grady v King | Sneaking and Lightfooted, one point each |
| 1 to 2 | Hold combat stance on every base chore | Nimble, no zombies needed |
| 2 to 3 | Jog the loot route on safe roads | Running, shared with Fitness |
| 3 to 4 | Alarm clock class: pull a crowd, crouch around the edge | XP scales with zombies nearby |
| 4 to 5 | Repeat with a bigger crowd, car ready | Same class, more students |
| 5 to 6 | Combat stance walking while looting | Nimble on the move |
| 6 to 7 | Long night crouch sessions near a horde | Stealth XP is per moment near them |
| 7 to 8 | Sprint laps at base when no zombies are near | Running |
| 8 to 9 | Keep all four habits | Months |
| 9 to 10 | Same | No books, no TV. Habits only |
Stealth run checklist
Before
Route
Habits
Your ticks are saved in this browser, on this device only.
Chapter 13
Tips, tricks and fixes
20 tips from the shadows
Setup
- One starting point in your main agility skill.
- Gymnast, Graceful or Runner.
- Never take Clumsy or Conspicuous for a stealth character.
- Watch Grady v King for Lightfooted.
- Check the sandbox hearing and sight settings.
Moving
- Crouch near zombies, always.
- Combat stance on every base chore.
- Jog safe roads.
- Fences and cars block sight.
- Fog is for crossing, not sprinting.
- Keep stamina for the escape.
- Indoors halves your noise.
Training
- Alarm clocks make crowds. Crowds make XP.
- Unseen is the rule. Chased is no XP.
- Moving is the rule. A corner is not XP.
- Nimble needs no zombies.
- Running shares XP with Fitness.
- Barefoot is quiet and dangerous.
- Stance is louder than crouch.
- Doors, cars and guns beat any stealth.
Fix-it table
| Problem | Likely cause | Fix |
|---|---|---|
| Sneaking does not level. | Zombies already chasing, or you are not moving. | Stay unseen. Keep moving near them. |
| Nimble does not level. | Not in stance, or walking into a wall. | Hold aim and change position. |
| They still see me crouched. | Line of sight. | Use fences and cars. Inconspicuous. |
| They hear me indoors. | Running in a house. | Crouch-walk. Indoors halves it, not removes it. |
| I get caught when I stop. | Exhausted crouch. | Keep a stamina reserve. |
| Running feels slow. | Low level, overweight, heavy bag. | Level it. Lighten up. |
| The horde followed me home. | Alarm clock class went wrong. | Car and exit next time. Lead them away. |
| No books for these. | Correct. | Habits and one VHS. |
| Glass in my foot. | Barefoot on a broken window. | Shoes. See the First Aid guide. |
| Stealth failed during a fight. | Fights are loud. | Stealth is for before the fight. |
Chapter 14
Ghost's test
7 questions. Get them all right and you are a ghost.
Chapter 15
Words and sources
Ghost's word list
- Combat stance
- Holding aim with a weapon out.
- Line of sight
- Whether a zombie can see you.
- Sound radius
- How far a footstep carries.
- Detected
- A zombie has noticed you. No stealth XP now.
- Running
- The Build 42 name for Sprinting.
- Graceful, Inconspicuous
- The 2 stealth traits.
- Alarm clock class
- Pulling a crowd on purpose to train near it.
How sure are we?
Every fact here was checked in September 2026 for game version 42.20.4. Order of trust: the official wiki, then well-sourced fan guides, then player reports.
- What each skill does and how XP is earned, the 50% hearing rule, barefoot halving, alarm clock training, the 4× starting point rule and the Running gain table. Confirmed on the official wiki.
- The multiplier numbers in the noise stack. Fan guides citing 42.18-era wiki data, cross-checked on 42.20.0. Approximate.
- Combat stance being louder than crouch. A fan guide.
- Job and trait values. May change.
Sources
- PZwiki (the official wiki): Nimble, Lightfooted, Skill
- Steam Community guide: All Crafting, Farming and Survival Skills XP Gains, Build 42.20
- Build42guide.wiki stealth and noise guide
- PZfans Lightfooted and skills guides for 42.19
- Bamboo Gaming skills database
- Projectzomboid.wiki stealth and noise guide