The game entry level for ATOM RPG is a little bit higher then in most modern RPG games because of its old school rules, so here some advises. It is not a walk through guide but rather some tips for new players how avoid the situations when you have nothing to do but refund the game. It’s great game so be patient and learn game world rules and you’ll love this game.

CHARACTER CREATION

Chose characteristics carefully as you won’t get new characteristic points with level up. There will be a chance to increase them permanently only 4 times and in special situations.
Make sure to have Dexterity about 8-10 if you are planing to fight and Personality about 6-8 if you are going to talk you way through. Intelligence about 8 is an asset for all type of character as it is the only characteristic you won’t be able to increase by items. So it’s good to decide at the beginning if you going to talk or fight you way.

KILLING NPC

Do not start killing NPC just because, even if you don’t like them. Know that the game let you do whatever you want and even very important NPC can be killed in world of ATOM and as a result you can miss some quest lines. But you still be able to finish the game.
And make sure that if you start fight in civil areas all location will probably get hostile.

SAVING GAME PROGRESS

Save the game before you start talking with any NPC as some special parts of conversation appears only ones! If you have failed a skill or characteristic check load he game and add some points to the skill on buff the characteristic with an item (perfume, vodka, hat, etc).
And make sure to save in different slots as sometimes you need to roll back.

SKILL ASSIGNING

For not getting to the situation when you do not have enough skill points to pass a dialog option do not assign skill points when you level up and keep them until you get the situation when you need to increase any skill.

EXPLORING THE WORLD

It is possible but I wouldn’t recommend to start massive world map exploration at the beginning of the game as you can run onto too powerful for you level enemies. There is no need to rush. You can but it’s better do not try to get to Bunker 317 too early in the game. And do not keep you stuff in trash containers, as they will disapear.

FIGHT THROUGH

If you want to fight do not try to start with melee build as some fight near the end will be extremely hard. Instead chose between Automatic Weapons or Rifles skill only. But do not invest skill points to those skill at the beginning of the game as most of the enemies will be armed with weak craft weapons or pistols and your start Pistol and Melee Weapons skills could be enough until you get an automatic firearm or a good rifle. Invest in armor perk tree. And always try to get best weapons and armor for you character and all party members.

TALK THROUGH

Invest in Speechkraft and Survival skills and you’ll be able to avoid all encounters with human enemies and mutants. But still there is going to be some fight you can’t to settle with high speech level and those fights are mostly kill-the-guy-like side quests and not story related. But anyway give a good weapons and armor your party members so they can fight for you.

FOLLOWERS

Be careful with giving your companions automatic weapons or grenades as they can do friendly fire. Check followers weapon skill and strength to make sure they will use the weapons you are giving them. Followers can be guided by clicking right mouse button and choosing the option for the follower. Orders should be given for every new turn and they remember only first given order. So it’s better to give an order when you almost finish you turn so you can ask them to shot a wounded enemy. If You have a little HP direct you follower to stay between you and enemy as all NPC always try to hit the nearest. The same situation when you companion is running out of HP. Remember if they die you won’t be able to resurrect them.

CRAFT

Here you can find all craft recipes.
In English
https://atom-rpg.fandom.com/wiki/Crafting
In Russian
https://atom-rpg.fandom.com/ru/wiki/%D0%A0%D0%B5%D1%86%D0%B5%D0%BF%D1%82%D1%8B_%D0%B4%D0%BB%D1%8F_%D0%BA%D1%80%D0%B0%D1%84%D1%82%D0%B0

Good information.

I also recommend that you save often, and have backup saves (in case things go wrong and your more recent saves don't fix it).

As Ataniz stated above, I also highly recommend using ranged weapons. Melee is much harder because you have to close the distance while taking fire from enemies, and ranged weapons can let you attack enemies while they have to close the distance. This is compounded when you're outnumbered, and getting shot at by 2-3 times your number really, really hurts.

When you learn new crafting recipes, you may want to keep a note about the ingredients, so you can actually craft them before you gain the specific knowledge to do so in future playthroughs. This makes crafting much more viable as a major choice in future playthroughs. (If someone has recipes somewhere online, I guess that's a choice too)

Some starter weapons, like the Zip Gun or Pipe Rifle, are very helpful for ranged characters, as you likely won't find a real firearm for a little while.

When dealing with Radiation & Toxicity, keep your eyes peeled when exploring new areas, you can spot areas that are radioactive/toxic before you near them.

Strength increases melee damage, carry weight, is required to prevent ranged accuracy penalties for some weapons(I think) and is a choice for certain dialogue options.

Dexterity increases melee accuracy and AP. It is arguably the most important stat in regards to combat.

Intellect gives more skills per level up, and can be used for certain dialogue choices.

Attention increases ranged accuracy and can be used automatically in dialogue to spot things.

With low Personality, many people don't want to make small talk with you, and may even not be willing to talk to you at all.

Weapon skills increase your accuracy with the relevant weapons by +1% per point. If your weapon skill is under the recommended value, it will have an accuracy penalty and will correct by +2% per weapon skill point until you meet the recommended weapon skill amount, at which point its accuracy will generally be tied with other weapons of the same category.

The Barter skill can change sell/buy prices with any NPC you can trade with, and can also be used to ask for discounts or haggling for a better reward. Every EVEN level of Barter moves the value of an item (whether buying or selling) closer to its base value by 1%, until it reaches the base value. Different merchants have different rates before you hit base value for both buying and selling.

Companions can be ordered to attempt to lockpick something, but they cannot use items that boost lockpicking such as a Prybar or Lockpicks (at least, their character sheet didn't reflect an improvement when I gave them those items) and they won't necessarily be able to apply their lockpicking skill in certain places (like a generator I came across which was locked).

If I understand it correctly, the Tinkering skill increases your success chance at crafting by +1% (though I'm not sure if it caps at 100%). Very Low means 1-25% success chance, Low means 26-50%, Medium means 51-75% and High means 76-100% (those are my findings thus far, I might be slightly off).

Companions can increase their Technology skill, but I've only once seen a situation where I was able to ask them to attempt to apply it.

Tools can be helpful, be sure to carry a knife or something similar with you. Oh, and I highly recommend getting some Vodka for the fisherman in Northwest Otradnoye, during the day.

Thanks for the comment and It's a good point to mention crafting. I'll add a link to ATOM Fandom Craft pages to the original post.

Another thing to add: when a weapon lists range, such as Short, Mid or Long, it's actually very unspecific.

Close/Melee range (same thing) means 1 tile away.

Short range can mean the max range is anywhere from 2 tiles away to 10 tiles away.

Mid range can mean the max range is from 11 tiles to at least 22 tiles away (possibly even more).

I haven't even properly tested Long range weapons yet.