Important! Most of the hints included in this second chapter of the guide are addressed to less experienced players. If you've spent a lot of time with "Shadow of Chernobyl", you will find most of these clues familiar or even obvious.
First of all, you will have to remember that "S.T.A.L.K.E.R.: Clear Sky" is not as easy or straightforward as other FPS games. It also has a lot of RPG elements which makes it more like an "Oblivion" or "Gothic" type of game. The most important thing you should remember about is that you're free to explore all the maps, without having to stick to main roads or narrow corridors. The world is divided to several sectors and you can visit them in any order, however travelling to some areas too soon may result in a quick death, especially if you don't have proper armor and guns at your disposal. The easiest way to find out the correct order is to focus on completing main quests, so you won't have to worry about the difficulty level rising rapidly.
You are free to go where you like, however you must be careful each time you've entered a new territory.
I guess I won't surprise you by saying that it's very difficult to survive in the zone, especially if you're not playing on the lowest difficulty level. You may have a different opinion at first, but I'm sure you'll agree with me once you've spent enough time exploring this postapocalyptic world. Your character may lose his life in a blink of eye and even by mistake, so you'll have to plan your each move and think about the consequences. Some of the most important reasons to stay cautious are the anomalies. If you ignore them, you might end up getting burned, electrified or poisoned. You should also remember about the radiation. There are some medical supplies to assist you with that, but in critical situations even they can't help... and obviously you must have them in your possession in order to use them. As a conclusion, you must stay away from all hazardous areas while travelling through the sectors. The only exception is when you're looking for stashes or artifacts (you can read more about those in the final section of the chapter).
Another important issue is to save your progress as often as possible. Your first "line of defense" are quicksaves, however you'll have to be careful when using them. You only have one slot for quicksaves, so if you save your progress in a dangerous situation, you won't be allowed to revert that. As a result, you should also create standard saves from time to time. I would recommend having at least 15-20 of them, especially since you may encounter various glitches and bugs and it can force you to go back a little to try again. Each time you plan on saving the game, make sure that you're not surrounded by any enemies, especially if you're travelling at night.
Anomalies are very dangerous and getting too close to most of them will result in a quick death.
"S.T.A.L.K.E.R.: Clear Sky" offers complete day and night cycle. This has its perks and disadvantages. As for what you can gain, it's much easier to surprise enemy units at night, especially if you turn off your flashlight and decide to use a silenced sniper rifle. The main disadvantage of moving at night is that you have to deal with a limited field of view. This means you won't be able to notice the anomalies or some of the monsters as fast as you'd wish.
Another crucial matter when it comes to survival is to identify enemy units and assess the threats. Check the next section of the guide if you want to find out more about the fractions. For now let's focus on something else. First of all, you'll have to remember that it's very unwise to attack someone who is much stronger than you or to come in contact with larger groups of enemy units. If you're surprised by these types of encounters, I would recommend that you run away. If it's not possible, find a good cover and eliminate your foes one by one. It's always a good thing to wait for allied units to show up, because you'll be much stronger as a team and you won't have to worry about your enemies focusing their attacks only on your main character. Watch out for heavily equipped soldiers and powerful mutants, especially since they can't get to you in a matter of seconds.
It's not wise to attack larger groups of enemy units. One of many examples is the military base in Cordon. Stay away from this area if you don't want any trouble.
You will be dealing with very similar enemy units to the first game, so if you've played "Shadow of Chernobyl", you shouldn't be surprised by these encounters. Obviously you'll come across members of different fractions, but for now let's focus on the mutants. You'll encounter a lot of boars and wild dogs early during the course of the game. The boars are easy to kill, but the dogs are much tougher opponents. The main problem is that they're fast, so you'll have to be a skilled player to eliminate them before they're able to bite you and inflict massive injuries. Later on during the game "jumpers" will begin to appear more often. Make sure to perform dodge maneuvers to avoid their primary attacks. You'll also be dealing with invisible creatures, so you'll have to be careful in order to prevent them from surprising you. To be honest, the only enemies you don't have to be afraid of are the zombies. They're very slow and they won't attack you unless you provoke them in some way.
Human enemies in "Clear Sky" are much smarter than they were in "Shadow of Chernobyl". The main reason for that is that they're capable of using grenades against you. Furthermore, it's very difficult to avoid the grenades, because you'll receive a warning at the last second and it's often too late to avoid the explosion by running away or finding a good cover. As a result, you'll have to observe how they react and attack them from larger distances whenever possible.
Watch out for invisible creatures, especially when you're travelling by night.