Because I'm not into those games. What can you tell me about the hit system? Do I get more hit points as I level up?

As far as I'm aware, your initial Health stat is based upon your starting Endurance stat and your maximum health increases each time you level up also based on your endurance. Some of the higher powered guns do have the ability to one shot kill you when you're at a low level, but you usually don't run into people carrying them outside of guards until later in the game unless you're super unlucky, instigate fights or go to a later game area early. Weapons have a damage range and won't always hit your for their maximum amount possible. You can also aim for certain body parts, some of which can damage health more than others or have secondary effects I think, though not sure how often the AI does that. Once you leave the ATOM base starting area there is a scripted fight you're expected to lose where you get knocked out and robbed of your starting gear but you don't die (and with a specific character build, tactics and some luck it is actually possible to win it). After that most battles will go on until you or your opponents die, and if you die it is game over and you'll have to reload a save, but generally enemies you face should be within your ability to beat most of the time if they start the fight. Along with health increases as you level up you're also able to find, trade and craft armor to offset incoming damage so you can take even more hits.

To add to what Chunkx said, difficulty has an effect on the chance of finding higher level encounters. So if you play on Expert or Survival(perma death) you're more likely to meet difficult enocunters that have higher end gear. It's also based on zones(so east of the mountain range is generally easier than the western portion of it). In general it's very similar to Fallout 2, Arcanum or Baldurs Gate in how encounters work, in that you're never safe from high-level encounters, but it generally favors throwing beatable ones at you(with more broad random strokes on expert).


Also to avoid oneshots \ dying fast, investing in 6 or 8 endurance isn't necessarily a bad thing. Can definitly go through the game with less(I personally run through with 4, and then boost it to 5 with a certain item), but the beginning does have a lot of quick deaths(not really one shots, but surrounded by multiple enemies alone) when you are running with a low endurance build.