Light and darkness in Project Zomboid

Build 41 gave every tile an ambient light level that was only slightly lower indoors, and a lamp lit just the room it stood in. Build 42 replaced that with light that travels: daylight comes in through windows and open doors and fades as it moves deeper into a building. The developers said before release that a room with no windows would stay dark even at midday.

Stockrooms, back offices and basements can be close to black during the day, and nights outdoors are darker than in Build 41. No source gives an exact percentage.

How dark the night gets is a sandbox setting called Darkness during night. Moonlight adds a little on top of the base value. The base values below are from pzfans.com (one source); the preset defaults are confirmed by a second site.

Build 42.21 raised the brightness of several lamp tiles.

• Vision. Zombies standing or crawling in unlit tiles are hard to pick out until they are close.
• Melee. No source lists a damage or hit penalty for swinging in the dark.
• Guns. Build 42 aiming applies a penalty for shooting into poorly lit tiles. The size of the penalty is not published (one source). See firearms.
• Reading. Reading is blocked, not slowed. If the light is too low the action will not start, so skill books need a lamp, a window in daytime or a light in your hand (one source).
• The map. On Apocalypse settings you cannot easily read the map in the dark without a light (one source).

Darkness cuts both ways. One breakdown of zombie sight says darkness lowers their vision radius from a base of 20 toward a floor of 10 (one source). A light in your hand gives part of that stealth advantage back.

Build 42 renamed the Build 41 Hand Torch to Flashlight and the old Flashlight to Flashlight - Heavy Duty. All strength and reach figures in this table come from pzfans.com item data for Build 42.21 (one source).

A cone light only shows what you face. An all-around light shows the whole room and also lights you. Angle-headed flashlights attach to webbing, leaving both hands free, and the Gun Light mounts on a pistol. A lit flashlight put into a bag switches itself off.

Matches are not light sources. The same source says vanilla Build 42 has no headlamp and no night-vision goggles.

Opinion Carry an angle-headed flashlight on webbing for clearing buildings and keep a lantern for the base.

A battery light drains only while it is switched on and held or attached. It loses one charge step every 10 in-game minutes, and each model has a different number of steps per battery. Figures are from pzfans.com (one source).

• The light must be empty before a new battery goes in. A partly used battery keeps its charge when you take it out.
• The battery charger is for car batteries. It does not recharge flashlight batteries.
• Propane and hurricane lanterns are drainable items with a use value of 0.007, but no source converts that into hours. Candle burn time is also unpublished.

On Apocalypse the power grid fails 14 to 30 days after the July 9, 1993 start. Rising and Outbreak use 14 days to 2 months, and Six Months Later starts with the power already off. Every wall switch, lamp and fridge stops at once. The emergency broadcast on the radio warns of it beforehand (one source).

A generator brings fixed lights back. By default it powers everything within 20 tiles and 3 floors above or below, and both ranges are sandbox settings. To connect one you need the How to Use Generators magazine, the Electrician or Engineer occupation, or Electrical level 3. Run it outdoors: indoors it fills the building with toxic fumes. Generator noise carries 20 to 25 tiles depending on the model (one source).

Lights are a small load, but sources disagree on the number. One Build 42 guide gives 0.0002 L per hour per lit tile, while the older Build 41 wiki figure is 0.002 L per hour per light. Read the live total in the Generator Info window.

If a room stays dark with the generator running, check that it is in range, that the fitting still has a bulb, and that the switch is not set to battery mode. A switch in battery mode ignores both grid and generator and runs on its own Battery.

Light bulbs. Lamps, wall and ceiling fittings and vehicle headlights all need a bulb. Bulbs can be taken out and moved between fittings; only vehicle lights need a screwdriver. Bulbs burn out over time, and the Light bulb lifespan sandbox setting controls how fast. Besides the normal bulb there are nine colored ones: red, green, blue, yellow, cyan, magenta, orange, purple and pink. This list is from the wiki page for Build 41.78 (one source).

Lamp on Pillar. This is the player-built outdoor light. The wiki recipe, written for Build 41, is 1 flashlight, 1 rope, 2 planks and 4 nails at Carpentry 5, with a light radius of 10 tiles (one source). It runs on its own battery, not on a generator: right-click the pillar to remove a dead battery and insert a fresh one. Build 42 item data tags four flashlights as usable for it (Flashlight, both Angle Headed models and Heavy Duty). No source confirmed a separate player-built lamp post in vanilla Build 42.

Campfires and headlights. A campfire lights a circle of up to 10 tiles outdoors that grows with its fuel. Car headlights reach about 36 tiles but are dim (one source).

Street lights. No source we could read states what happens to them at shutoff.

Does light attract zombies? Sources split here. pzfans.com says a lamp has no pull of its own and flicking a switch makes no world sound. Light makes you visible, so a zombie with line of sight to a lit window or a flashlight beam can spot you. Another guide says flashlights draw zombies from farther away, without giving a distance (one source). Either way, close curtains in lit rooms and switch the flashlight off when you do not need it.

Cat's Eyes. This positive trait costs 3 points and is described in game as better vision at night. It lifts very dark ambient light to a floor of 0.2 before the night setting is applied (one source). It is passive, does not widen your view cone, and does not replace a flashlight inside a windowless room.

Opinion Cat's Eyes is worth 3 points on Pitch Black or Dark settings and for characters who travel at night.