Zombie
Template:General Zombies are your biggest threat, roaming Knox County in the hundreds.
There is only one type of zombie which is the traditional slow moving type. They are attracted to noise, fire and the sight of a human.
Zombie Mechanics
Pathfinding
Responding to claims of zombies 'cheating' to locate players, Project Zomboid developer Chris "lemmy101" Simpson explained the nature of zombie pathfinding:[1]
"Zombies can pathfind a total of 20 tiles to reach you. Seems like a lot but any less than that and they fail miserably to ever come upstairs to get you or to navigate around a gap in a fence or something. This all means that if you're at a window and a zombie sees you from outside, it will attempt to pathfind to your current spot, and if it's under 20 tiles travel distance it will work out a route to get you. A bit too intelligent for a zombie perhaps, but until we can balance it such that the threat is still there without this, then it is necessary. If the zombie is over 20 tiles away from you then it will continue to 'wander'.
If a zombie is within a few tiles distance to you, then instead of path finding it will just lunge at you, moving directly toward you irrespective of things in the way.
If you make a sound that's in range of them (and is the relative loudest sound they hear from their position) they will head to a random point within 50% of the range of the sound. So hearing a shotgun blast from 40 tiles away, they will head to a random location within 20x20 around the source of the sound. If another shot occurs when they are 20 away, they will head to a random point in a 10x10 square around the sound.
So if a zombie hears footsteps coming from a few tiles away, they will pinpoint it accurately enough to head to the door to that room.
Zombies will always head toward the sight of flesh, ignoring all sounds. At moment this only includes player + Kate, but in time any living flesh will be equally attractive."
Horde Behavior
Project Zomboid developer Lemmy provided further information on the zombie's hoarding behavior:[2]
"At the start of the game, there are three hordes. 50% of the total map zombies are put in a horde, the others are randomly distributed around the map.
Zombies not in the horde head toward the nearest horde, while wandering and outside the player's sight. The hordes all move around the map at a slow speed, heading to a random point on the map, then another, then another."