Zombies

Zombies are the main antagonist of The Dead Linger. They are humans or animals infected with the HNZ virus, which can be spread through bodily fluids or physical contact (especially bites), and possibly through other means. They are afflicted with necrosis, severely reduced intelligence, and display aggressive hunting behavior. Most noticeably, HNZ patients can stay alive well after an uninfected person would most certainly be considered dead. Zombies are colloquially known as "Zeds", after the British English pronunciation of the letter Z. Just like world generation, zombies are procedurally generated: different faces, clothes, body types, etc. make for very individualized zombies.

Anatomy
The zombie condition is persistent, and zombies are much harder to kill than uninfected humans. They will only remain dead if their head is destroyed or severely damaged. However, necrosis makes zombies prone to dismemberment. This can have tactical advantages for a human eager to survive: shooting off zombies' legs, for example, will slow them down. Zombies have 80 health points to date in the alpha.

Senses
Zombies have four senses with which they detect their prey:
 * Sight - If a zombie sees a human, it will give chase. They see less far in dark areas.
 * Smell - Zombies cannot currently smell, but in the future they will smell a player if the player is hidden nearby for too long.
 * Hearing - Every action emits different levels of noise. Walking, shooting, hitting, building. etc. can be soft or loud. Walls affect dispersion of sound.
 * Touch - Don't accidentally bump into a zombie in the dark.

These senses will be affected by weather conditions. Thunderstorms will make it more difficult for zombies to hear players, night makes it harder for them to see humans, and so on.

Drops
Zombies have about a 2% chance of dropping a random item when killed.

Behavior
Zombies have lost most of their higher mental functions, and as such are not very active. They are eager hunters, however, and sighting a human is sure to rouse them. A zombie has three basic states of mind:


 * Idle - Shuffling around, apathetic.
 * Investigating - The zombie has recently detected a human through sight, smell, or sound. It will investigate the area of the disturbance.
 * Aggressive - The zombie knows a player is around, and is either on the lookout or actively giving chase.

Movement
Not all zombies are equally fast. They have good stamina either way, but their maximum speed comes in two types:


 * Slow - These zombies are slower because they are near starvation.
 * Normal - The most common type of zombie.

In the future zombie speed will be based on the walking animation the zombie is using. An example would be a zombie with a limping animation will be slower than another zombie who isn't limping.

Zombies cannot climb ladders or high ledges but can climb through windows and over low fences.

In the future zombies will be able to crawl and grapple onto vehicles. Zombies will not be able to swim, but they will thrash around in water and can cross shallow streams and pools in this way. A deep area of water between a player and the mainland provides a modicum of safety.

Hordes
Hordes are large groups of zombies that move about the world. Players caught off guard can be surrounded by zombies in what was originally believed to be a safe area.

Attacks
Zombies only use various melee attacks; there are no plans for armed zombies or zombies with ranged attacks. Being attacked increases infection risk. Zombies also have the ability to break down barricades, doors and windows.

Hitting
A zombie's most basic attack is hitting something with its hands. A single hit from a zombie causes 16 damage. It is possible to dodge a zombies hit, though it takes practice.

Grappling
Zombies will be able to grab players, knock them down and hold them in various parts of the body. This will restrict the player's movement, and as such make them easy to bite. A player can escape by causing sufficient damage to the zombie holding them down. This is not a quick time event.

Biting
Zombies and strays can randomly bite a player while attacking. In the future biting will only occur after the player is unable to break free from being grabbed by a zombie. Once the bite occurs the player will risk infection.

Population
Zombie numbers depend on the population density of an area, but there is some randomization involved. In practice, this means that a large city will have more zombies than a forest, but two cities may have quite differing zombie populations. As of May 2012, up to 500 zombies are confirmed to be possible in a particular area. Statistically, one out of 250 spawned zombies is a dog instead.

Spawn mechanics
As of April 2012, the details of zombie spawn mechanics are not yet clear. However, zombies will never spawn directly in front of the player. In a forum discussion, Design Director Geoff Keene discussed several ways that zombies could spawn. He noted that most people preferred the idea that zombies would only spawn around other zombies, meaning that a player's camp would be safe from zombie spawns until it was breached by a zombie, after which more zombies could spawn inside. The area type affects the quantity and type of zombies.