Originally, as a stalker, we had to both survive in and live off the environment, and could suffer the effects of hunger, exhaustion, radiation and health...
Yavorsky: After a series of play-tests we decided to simplify the micromanagement of the player's survival parameters and make it all less complicated compared to the original implementation. Thus, we removed the need to sleep and eat. Food, however, remains in the game and serves specifically to restore your health a bit (a kind of alternative to medkits). Exhaustion comes if you are carrying too much weight - getting overloaded with weapons, items, artifacts, food etc (each object in the game has weight) does not let you run or even walk (depending on the weight you're trying to carry).
Keeping an eye on your health bar and staying away from radiation and anomalies remains very important. Radiation sickness (you will see a characteristic visual effect and radiation sign on screen) makes you lose health very quickly, so make sure you've got anti-rad pills or vodka with you to cure the wounds.
Speaking about wounds, depending on the injury type, you may start bleeding (apply bandages to stop it), so watch out as other NPCs/creatures may hunt you down by traces of blood on the ground (you may do the same to them).
A stalker's main role is to scavenge artifacts from the environment to sell on to scientists and corporations. What types of artifacts are we talking about here, and can they be used by the player?
Yavorsky: Artifacts are items which absorbed the energy of the anomalous spots generating around them. In the game, we provide for a number of different types of anomalies (such as gravitational, electric, radioactive etc). Artifacts also differ in terms of rareness: very common artificts have low price, while the rare ones can be sold for a very good penny.
Apart from their monetary value, artifacts may come in handy to the player in tough situations. Each of the artifacts is characterized by certain abilities which the player may apply in need. To apply an artifact, the player simply needs to put it on his belt. The abilities of artifacts, however, do both good and bad on the player, so make sure you clarify what effects it will have on you before using the artifact.
Let me give you a couple of artifact examples. 'Stone blood' is an artifact generated by a 'whirligig' anomaly. Visually, it is a deformed, reddish object made of compressed, oddly twisted, polymerized scraps of plants, soil and bones. It is believed that the strength of people perished in the anomaly is contained in the artifact. As the Zone is plentiful of dangers, you wouldn't be surprised to hear that 'stone blood' is quite common, and hence is not very pricy. The artifact is able to speed up healing of your wounds, but at the same time softens your flesh and hence makes you more susceptible to damage.
'Flash', another artifact example, is formed in the 'Electro' anomaly. It is a translucent, amorphous object with light beams pulsating under the surface, occasionally generating miniature lightning-sparks. 'Flash' can help boost your stamina and provide some resistance to electricity, however at the same time makes you highly vulnerable to radiation. The artifact is of primary interest to scientific organizations, collectors and jewellers.
