If you are aiming for achievements do not lower difficulty to test the game at any point, and attempt to finish the game with as little chance of using checkpoints as possible.
This game's save system is not the most flexible in the player's name.

To acquire 0 footprint the player must avoid alarms, knockouts, kills and trace of any kind being left behind at all costs.
This means no shots fired, no getting caught on the hacker end, no ddosing and no leaving doors broken instead of just unlocked.
Lastly, you should always use your default outfit when provided the choice, as it is far more camouflaged and less detected than any alternatives.

Simply put, if you don't like a no knockout playstyle, you probably won't enjoy getting 0 footprint.


Playstyles are "ghost, blitz, macgyver, pacifist and anonymous".

• Ghost: You'll acquire this naturally in the process of getting 0 footprint. It simply means nobody witnessed you intruding.
  
• Blitz: To acquire blitz you'll have to go faster than the par time in the mission select screen.
  This should be easy if you follow this guide, but even easier if you use distractions like the pager with planning.
  Acquiring this means you'll have to be as fast as possible, and won't have time to read notes or observe too much. It's recommended by most you grab this on a second playthrough as a direct result.
  
• Macgyver: To acquire macgyver simply don't bring a gun into the mission, and never pick one up.
  Considering the parameters for ghost involve never using guns to begin with this won't be difficult to attain.
  
• Pacifist: Pacifism involves not killing anyone. This should be easy if you're already going for 0 footprint, and will happen naturally as a direct result.
  
• Anonymous: Never get caught by the system administrator when you're hacking.
  Don't worry, you can leave the hacking screen in single player and you'll essentially "freeze" the sysadmin in his tracks. This one should be easy so long as you pay attention to what you are doing while hacking.

Lastly, it's important to note that while I acquire all secondary objectives and go out of my way not to use items in this guide there is zero reward for doing so; feel free to simply ignore secondary objectives and use pagers in the name of a faster completion time.

Something to keep in mind while playing: Camera placements, locked doors and keypad codes are random. Patrol patterns are not.
As a direct result your best course of action is to learn the patrol patterns of the guards in a level, and then route around that given the layout of the hackable items.
Obtaining intel while doing a perfect run of any kind is incredibly unlikely due to the random placement of intel. If you are able to do it feel free to post in the comments, I'd be happy to update the guide in a way to encompass more accomplishments per run!

Each of these videos demonstrates the most practical, minimal route I've been able to find in every level.
Ghost blitzing these, especially on harder difficulties, isn't recommended unless you've played through the game at least once.

There's less than 4 moving guards in the entire level you'll have to sneak past, making this level fast and easy.
The only necessary knockout in the entire game is at the end and isn't counted against you. Be warned however if you kill him you won't get the pacifist playstyle.
Gameplay @ 2:15

Copenhagen is the longest mission in the game. As a direct result mastery of the layout is practically required to make it within blitz time.
If you're aiming for secondary objectives like I am you'll be at the mercy of the RNG for doors and cameras while aiming for the second story secondary objective in the final segment.
Gameplay @ 3:20

The quickest level to do in the entire game.
If you're nuts you can try and luck your way past the guard in front of the archives, but your safest option is to simply listen for his name and hack the marked computer as Martin once the conversation reveals his name.
Special mention goes to the fact that the only guard you truly need to sneak past is on the third floor in a circular route.
Gameplay @ 4:15

If you're willing to skip conversations this mission can be passed incredibly quickly.
The only guard you'll have to worry about, if you route properly, is Xenia.
Gameplay @ 3:55

If you can bluff your way past the front door the rest of the first segment should be easy.
The second segment is one long set of incredibly tight circumstances. Memorization of potential guard patrols and placements is a must.
Gameplay @ 3:44

Because you've done the game at 0 footprint this level will have more guards, but ultimately be much shorter than had you made more than 50 footprint.
Just be aware of patrol routes and this should be one of the more simple levels to perfectly run.
Gameplay @ 3:43

This mission only occurs if you have done a sub-50 footprint run up until Paris.
Annoyingly, this mission's results are charted down as though it were the next mission's. This means that your Safehouse debriefing and your progress will act as though you've already done the proceeding mission.
I've talked to one of the developers and the likelihood of getting this patched this late after the game's release is quite low.
Gameplay @ 2:00

If you played through the intermission mission you should know the exact layout of the last segment of this sneak by now.
Gameplay @ 1:35

The first segment should be an absolute cakewalk.
Just be aware that the entire second segment is the most vertical the gameplay gets. I'm able to get by two guards having a conversation because while they're talking, guards won't investigate near-sightings, they'll only go full alert or not notice you.
As well, take note that during the killhouse segment guards above and below you can potentially notice you. Extra awareness of your surroundings is absolutely vital during this segment.
Lastly, be aware you cannot blitz this mission and talk to the target as he takes a solid five minutes to talk to in full.
Gameplay @ 2:04

Hopefully this guide results in a 100% run for you.
If you can find a way to stretch this into intel acquisition too let me know!

Hit like and comment if you found this guide helpful, it's appreciated more than you'd think!
Be sure to let your friends know about Clandestine, it's a sorely under appreciated game, and don't be afraid to add me on Steam for a coop session!