S.T.A.L.K.E.R. is a shooter, an RPG, a trading simulator, and a survival horror game all wrapped up in one. It has a rich and deep game world, but its depth has probably scared away most people from trying to tackle this ambitious series.
Other games, like F.E.A.R. or Dead Space use the same tactics as horror movies to try and scare us. They build moments of tension and spring monsters out of closets to make us jump out of our seats. S.T.A.L.K.E.R. builds a terrifying world and abandons you in it, fighting for survival.
It doesn't attempt to create scary moments, it just has a scary world. The payoff isn't immediate -- and you won't be immersed in the world in five minutes while hanging on to the edge of your seat -- but if you give it a little bit of time and effort, you'll be richly rewarded.
The world exists with or without your intervention. Gun battles don't start every time you show up, and people don't sit around waiting for you. NPCs have shit to do, and they don't need you there to do it. Caravans travel around buying and selling, and monsters will roam around eating people. You can interact with all of this detail, or you can just ignore it and let it provide you with a fantastic backdrop for your adventures.
If you are looking to jump into S.T.A.L.K.E.R. for the first time, I've got some sweet mods that will make your experience much better. Artistpavel has compiled all of the best mods for each game in the series into easy-to-install .EXE files.
The S.T.A.L.K.E.R. Complete mod series aims to enhance the games without changing the gameplay, story, or core elements. It simply makes them better. The graphics are enhanced insanely, bugs are fixed, the translation to English is improved, and you can keep playing the game after it ends.
If this is your first time playing any of the games, you will want to start with either Shadow of Chernobyl or Clear Sky. Shadow of Chernobyl is the first game released, but Clear Sky comes first chronologically. I love Call of Pripyat but it's not a great one to start with since it just drops you into the world without explaining much.
Those of you not using the Steam versions will want to make sure that you have the latest patches; otherwise, your game won't start.
Shadow of Chernobyl
Call of Pripyat
If you have over three gigs of memory and you experience any sort of crashing, there is a patch on each of the Complete download pages. This should clear up any issues, but only install it if you are having problems. Extract it and copy all of the files into your game install folder. Run START.bat and hit "A" to add the three-gig fix.
If you love modding games, check out more of The Weekend Modder's Guide. Have a favorite game that you would like me to cover or a cool mod to suggest? Go ahead and post it in the comments. I promise that I read all of them, and I try and respond as much as I can.