Radiation zones (sometimes referred to as "radiation anomalies") are a central aspect to the game. Their main purpose is to pose a challenge when exploring the open world as they can contribute to limiting the areas in which the player can explore safely. Radiation zones contain more zombies than outside areas.
Radiation zones are always in specific areas of the map, usually around structures or areas of importance such as the Tesla Towers. One other example location is the village of huts on stilts that can be found near one of the fast travel points in the early game, which is "protected" by an area of radiation around it.
HUD/sound changes Edit
Once you enter a radiation zone, your heads up display (HUD) and vision will very obviously change, providing an instant visual cue that you are in a radiation zone and therefore in danger. You will also hear different background noise as well as a distinctive clicking reminiscent of a Geiger Counter. While this can be confusing and disconcerting for players new to the idea, it will quickly become apparent to even the most inexperienced player what is happening. If you are just out exploring without a radiation suit, then it is highly advisable to turn around as soon as you experience these changes.
The main danger posed by entering unprotected into a radiation zone comes from radiation sickness, a damage-over-time (DoT) infirmity which is automatically inflicted upon you when you enter a zone. It slowly gets worse as you spend more time in the zone, and can even get to the point where it can kill the player. It is represented by a radioactive hazard symbol which appears on the middle of your screen under the health and hunger bars. It will start actually damaging the player when the circular bar around the outside of the icon fills up. This can happen eventually even if you are "protected" from radiation by the radiation suit.
Defences against radiation Edit
Damage from radiation is not "damage" in the conventional sense. Because of this, any armour you wear will not protect you from it, or even slow it down, much the same as damage from bleeding (once it has been sustained). Instead, there is a special item called the radiation suit to help protect you, and even a special armor slot to equip it in.
Original section (will be deleted when I have finished this page):
"Radiation AnomalIes give radiation sickness, which can only be combatted with radiation pills, if you stay in them too long. Going in an area with radiation is highly inadvisable without a radiation suit, although doing so even with one should not be done for no reason as it slowly wears away at the suit while you are wearing it. Because of this, you should always use haste and set clear objectives while exploring irradiated areas to avoid dawdling and unnecessarily damaging your suit. One strategy could be that you set a time limit, say two minutes, for your exploration, after which you could teleport out of the area to one of your fast travel points."