Note that this NOT a speedrun nor a seamless run, but I have done my best to edit out the parts where I failed or was too lucky in order to provide a more reliable way for you to follow. I hope that you find it useful. Please leave a like if so and feel free to comment and ask questions if you need more help.

Chapters*

1. Moscow - 0:00
   
2. Winter
   
3. The Volga - 0:36:15
   
4. Spring
   
5. Yamantau - 1:48:15
   
6. The Caspian - 2:03:10
   
7. Summer
   
8. The Taiga - 3:34:20
   
9. Autumn
   
10. The Dead City - 4:21:25

* I have removed the scripted sequences/chapters and cutscenes where not relevant as you cannot die or make mistakes there. When I played, I skipped and saved time where possible. If you would like to build a relationship with your crew, listen to them and take part in the activities on The Aurora. It may help but is not required for the best ending.

Update: You can use this for Iron Mode too. Just skip the optional parts. Iron Mode can be played in New Game Plus as well as on any difficulty, so it's much easier than Ranger Hardcore.

This is the first chapter and is relatively easy.

• The tunnels are easy and if you die, you can reload. Not much to lose there.
  
• Once in open Moscow, you can run and skip all the mutant encounters. You don't have to wait for Anna to catch up, she will respawn where needed. Make sure to crouch behind the bus (0:06:45) and wait for the mutants to pass by.
  
• When you make it into the first bandit hideout, listen to your companion and follow his instructions to avoid combat. After you meet with Anna and are on your own (0:21:00), make sure you pay attention to the enemies' conversations so you can tell when they move away.
  
• For the forced combat sequences, try to hide behind objects and let Anna do all the work. She should be able to take all the enemies out without any of your help, but in my case I had to assist a bit (0:28:00).
  
• The enemy train part is easy as there are clear ways to sneak around and avoid all combat. You can unlock the optional achievement Brakeman (0:32:00) - detach the first two train cars with the levers at the end of each of them.

This is the first open-world chapter and the third one overall, where you will work to unlock the Duke achievement.

• You earn a morality point at The Church is (0:42:00), if you are not spotted.
  
• Make sure to visit Duke when instructed and sleep so you can walk to the train car in the dark. Once inside, you can run and skip quite a bit of the mutant encounters (1:10:00).
  
• Try not to alert the enemies at the bandit camp with the passenger train car (1:19:00). If you do, then make sure to knock them out and leave the surrendering ones unharmed to avoid any bad karma.
  
• You do not need the Teddy Bear and Guitar, but if you want bonus morality points to balance out any mistakes, you can complete these side missions.
  
• Avoid combat at the next enemy encounter with your crew where you steal a boat (1:40:00). The bandit at 1:42:20 is particularly tricky as he walks around if you don't distract him when you climb up. If that happens, try to knock him down and remain unseen.
  
• Same with the fanatics hideout at 1:45:00 - avoid combat. Tricky one is the enemy at the stairs shortly before the door to the leader - I had to knock him out as he would always see me.

If you succeed, Duke will jump with you on the train and join you for the rest of your journey. The achievement will unlock at the end of the chapter.

Yamantau is the fifth chapter with forced combat sequences. Luckily, it is a relatively short one too and you can let your team do most of the work. Look for ammo and loot, especially molotovs, between sections.

• Crouch next to Miller at the start and look back. If you are hit once or twice, use a medkit. Note that you may die a few times, but this spot has so far been the most reliable one in my experience. Crouch in the lift too.
  
• Finish the wave after the first door. There are 7 enemies, 4 of which will attack you at the very start, the others you can take your time with. The last one only spawns when you try to proceed to the next area, so be ready for the surprise.
  
• For the second door be ready to run and shoot anyone in your way. You can avoid the rest and save some ammo.
  
• After the vents part, stand in the narrow area to let the cannibals approach you one by one. The final enemy will be by the fridge and he won't see you, so shoot him or just skip him.
  
• In the next area, first shoot the enemy with a molotov, then stand at the entrance and shoot the two fuel tanks and wait for the rest of the enemies to come one by one.
  
• For the armoured enemy, use explosives and molotovs. Hit him directly with them so he is stunned and wait for each molotov's fire to burn out before you throw the next one. For the area after it, run forward and shoot the enemy in front of you, then open the door as soon as possible to skip the combat.
  
• For the lift bit, crouch and hope you don't die. You may have to reload, but it's a short sequence. Crouch in the train as well, I don't think you can die there this way.

This chapter doesn't matter for morality but can be difficult, so I included it anyway.

The Caspian chapter is the longest and most inconsistent one so far. You will be presented with optional objectives, which you must follow if you want Damir and Full Strength achievements, but can ignore if you only want Ranger Hardcore achievement.

• +1 morality point for the attacker at the start (2:06:50), so make sure you don't kill him, but knock him out instead.
  
• +1 morality point for the rescue of the slaves at the ship on your way to the main mission (12:10:20).
  
• Make sure you visit the boat near the lighthouse and sleep until dark to make your next mission much easier. Note that as you wake up, an enemy will walk in to search for you, so knock him out and same for his buddy outside.
  
• In the next bit (2:17:00), do not kill any of the enemies, but knock them out instead. If dark, the ones in front of the lighthouse won't know whether you are one of them or not, so use that to your advantage.
  
• +1 morality point for retrieving the photo in the underground with spiders (2:31:30). Give the canteen to the little girl once back to your crew's hideout, not sure if this counts, but you will have it as part of the previous task, so why not.
  
• Before the mission with Damir, visit the same boat from before and sleep until it's dark to make stealth easier (2:44:30). In the caves, you can skip all mutant encounters if you run (2:50:50).
  
• Optional: +1 morality point if you free the slave near The Oasis.
  
• +1 morality point if you are not spotted and do not harm any slaves/enemies in The Oasis.
  
• For the attack on your crew (2:57:40), you can skip it if you run away which at certain point of distance will cause your team to win automatically.
  
• +1 morality point for the sniper optional mission (3:01:50). Craft weapon of choice from your hideout, I used pistol with sniper scope.
  
• +1 morality point for freeing the slaves in the ship (3:09:10) - you can kill the enemies there, but do so silently. It is possible to knock out all of them, but I found that too inconsistent to recommend.
  
• +1 morality point if you avoid combat with the slaves as requested by your team (3:20:05). This is very tricky and unfortunately inconsistent. Listen to their conversations and let them finish where possible. You can reload if you are spotted and retry the first half. Once you make it past the master who chokes, it may auto save and lock you in a bad position so try your best there.
  
• +1 morality point if you knock out the slaver at 3:25:30.
  
• Optional: +1 morality point if you knock out the slaver with the woman but keep in mind this will alert everyone and combat can be tricky in this area. It's not too bad and if you think you need the morality point, do it.
  
• Stick to the left at the start of the combat part, there are molotovs on the table nearby, which you use for the armoured enemy later.

If successful, Damir stayed with you and the achievement unlocks at the end of the chapter.

The Taiga will be fairly straightforward in order to keep Alyosha from becoming crippled. You can complete the entire chapter without killing a single enemy. If on lower difficulty than Ranger Hardcore, you won't even have to knock out anyone.

• +1 morality point for saving the student from the wolf at the start (3:35:00).
  
• +1 morality point if you don't kill any students at the first hideout (3:37:00).
  
• +1 morality point if you do the same at the next hideout (3:49:00). On difficulties below Ranger Hardcore, you do not have to knock out the enemy at 3:52:00, however on RH he would always see me so I had to do it.
  
• You can completely skip the next enemy hideout (3:54:00).
  
• For the bear encounter, simply lure it away once, then cut the rope and climb up the ladder. Use molotov if you need to, make sure to collect all useful loot from the area before the bear comes.
  
• Make sure you sleep until dark before the next encounter (4:00:20). I am always seen there, so my aim is not to knock out anyone and make it out alive. You may need to reload as I did.
  
• Optional: Sit down by the crazy man in wheelchair and have some tea. He will appreciate it and you will unlock the 5 o'clock achievement.
  
• The spiders part is fairly easy (4:11:00) if you run all the time. The fuel is upstairs by the door.
  
• For the second bear encounter, use the molotovs from the graveyard and any explosive bolts you have - there are more near where the bear is during the cutscene. Fight it until it starts to approach you slowly, which will cause to hit you as part of the end sequence.

Hopefully, Alyosha is all safe and sound with you now and the achievement unlocks at the end of the chapter.

This is the last chapter. You will have already determined the outcome of Full Strength, however you can still make choices in this one.

• Let Miller kill most of the mutants by picking a relatively safe corner and throwing molotov if you are in trouble. Mutants will attack you whenever Miller is preoccupied so, be ready to strike back.
  
• Most of this chapter is scripted, but once you reach the boy's hideout (4:42:00), take Miller's weapon as it will make the next parts easier.
  
• In the putrid tunnel, make sure to shoot the weird mutants that spit at you, they are so many ... (4:50:00)
  
• Once you reach the blind mutants, crouch and keep distance from them as they can hear and smell you. For the part where you have to deal with two (5:14:10), land on the platform after you turn the power on and wait for the noise to start, which will distract them and you can pass easily. It will take a while, so be patient.

If you don't kill any of the blind mutants, you will unlock the Guide achievement at the end of the chapter.

Full Strength and Hardcore achievements will unlock during the Epilogue before the credits, which is after you drive with the kid to the train and watch The Aurora crew save Artyom. In my case, only Hardcore unlocked as I had already unlocked the other ones in previous run.