I have gathered some useful info alongside some tips and tricks that I would like to share with people.

There are 15 multiplayer achievements in total, and although most of them can be obtained in about 30 minutes, some of them take considerably more time to obtain than the others.
This is the ranked achievement which will take about 1-3 hours not counting looking for a group.
And the 2 grinding achievements (LV60, shopaholic) which can take about 6-12 hours depending on the method you use.

The servers are mostly dead so if you want to get the achievements you have basically no other option than to boost with other players. You can find people to do this in the discussions for this game.

This multiplayer mode can be quite buggy, here are some bugs that you may encounter and how to fix them.

• Crashing when alt tabbing
  If you use fullscreen the game might crash if you alt tab or use steam overlay. So to be safe, it's best to turn fullscreen off.
  
  
• Camera not working
  Sometimes when starting a match the camera wont work and your mouse cursor will be on screen. To fix this, turn fullscreen on and off again. Make sure to apply the changes when you toggle it.
  
• Incompatible dlc
  This game has multiplayer dlcs, which not everyone has. This can create some problems with inviting people to lobbies.
  
  The best way that I found was by having someone without the dlc make the lobby and invite the others. They will be prompted with a message asking if they would like to turn the dlc off, after that they should be able to join the lobby.
  
• Unable to reach host
  When joining lobbies you sometimes get a error message saying the host is unreachable. I don't have a complete fix for this but most of the times restarting your game should help. If it does not, make a new lobby. If people still have trouble joining, have everyone restart their game.
  
• Microphone
  Be aware that your mic is automatically turned on in game. If you do not want this then you have to go to options > Game play > always transmit voice chat > off

These achievements can be done with just 1 extra person, more also works. It's best to start a private free for all match on the map underground. This is because FFA has the shortest respawn time and underground is the map where you can find each other the fastest after dying.

Set the time limit to 20 minutes, executioner off and at 100 kills.

"Kill 20 enemy players in multiplayer using a turret."

The turret is a mounted machine gun that is only in a couple maps. If you are in free for all on the map underground there is a easy way of getting this. Destroy the red barrels under the bridge and let the person getting the achievement kill you with the turret. If you can't find the turret, it's on top of the boat.

You should respawn on the far side of the map. But because the bridge is down the turret can still see and shoot you. 90% Of the time you should respawn in that exact same place allowing the turret to keep killing you as soon as you spawn. This may not work if you have more than 2 people, but then the turret also has more targets so it should be fine.

Also it may be useful to know that in order to leave the turret you have to press shift.
Where you should respawn


"Kill 10 multiplayer enemies using your melee attack."

Press F to melee, both backstabs and normal hits count for the achievement.


"Catch a player in a snare trap in multiplayer."

There are rope traps around the map which you need to use to entrap someone. If the achievement does not work, retry it in a different match.

Example of a rope trap and its location.


"Kill a zip-lining enemy player in multiplayer."

If you shoot someone on a zip line they will fall off. In order to kill them while they are on it, your first shot should be the killing blow. This can be done by shooting them in the leg a couple times before they jump on.


"In multiplayer, escape death 3 times by using the rope ascender."

In order for the game to count you as surviving by using the rope ascender, you need to be wounded and then jump on a zip line and press E. This can again be done by having someone else shoot you. It can also be done solo by standing in fire for a while or hitting yourself with an explosive.

If you are on the map underground i recommend using the zip line right next to the bridge. Make sure to go up the zip line not down.

Also only the Solarii have access to the ascender except on free for all where everyone has it.
In my opinion the best zip line to use on this map


"Survive 10 explosions in multiplayer."

As far as i know this cannot be done using red barrels they will either not hit you or kill you, no in between. There are various explosions that players can equip that will work better than red barrels. So either use them on your self or have someone else use them on you.

By default survivors start with a grenade launcher that can be used for this. You can replenish its ammo by going to yellow crates or dying.

These achievements can be obtained with a minimum of 3 people. They are short achievements you can get pretty quickly and can be combined with the ranked achievement.

"Revive a teammate in a multiplayer match."

This can only be done in the mode rescue as the survivor team. you can either have the enemy team kill a teammate or you can shoot your teammate with an explosive.

After your teammate is down walk up to them and press shift, this is really inconsistent so just keep spamming it until it works. Also you do not need a med kit to do this.


"In multiplayer, be the only player on your team that isn't dead or downed."

You should get this while doing the revive, if it did not unlock for you then ask your enemies to kill your teammates.


"Kill 2 multiplayer enemies with a single explosive."

Get 2 people on the enemy team, if you don't have any explosives then ask them to stand next to a red barrel.

"Win a ranked match in every multiplayer mode."

This may not take as long as reaching LV60, but it is by far the most difficult and annoying one to get. For starters, you need a minimum of 4 people to do this.

To create a ranked lobby, simply search for one. The game will create one if it can't find any (which is most likely the case nowadays). From there you can either invite the other players or they can search for it themselves.

There are 2 ways of getting the wins, the normal way and the forfeit way.

The normal way is just by having 1 team win by doing the objectives. The problem with this is that respawn timers are quite long in non free for all games and you need to win 2 out of 3 rounds. So this method can take multiple hours to get everyone their 4 wins.

The other way is faster but can be buggy. Winning by forfeit can be done by having the enemy team leave. This way the match will end after a couple of seconds and give the remaining team their win. So you don't need to play 2 full rounds. But this doesn't always work in which case you need to restart the lobby and do it again.

Some general tips for doing it the forfeit way:

• use alt+F4
  Using alt+F4 instead of exit to main menu seems to result in less problems.
  
• Team Death Match
  In TDM it can be useful to have the winning team get a point ahead before the other team leaves. This can prevent a draw since both teams have the same objective.
  
• Free For All
  You don't need to leave for free for all. Their is only 1 round, fast respawn timers, and you win by getting 8 kills without dying. Also by doing FFA the normal way you don't need to set up a new lobby every time.

"Complete a match in all multiplayer modes."
you will get this after doing the ranked achievement, there is no need to do this separately.

"Reach level 60 in multiplayer."

This will take a long time, you will need around 1.770.000 XP.
As far as i know their are 2 ways of doing this legitimately.

Create a private rescue match on beach. Change the amount of med kits to 20 and start as survivor.

When in game just collect the med kits until the round ends if you do it fast enough you should be able collect all 20 med kits in 8 minutes or so, which will result in around 27k XP.

In between the round switch you can exit to main menu and restart the match as survivor. There is also a perk that will help you collect the med kits faster called second wind, it allows you to run faster.
This method is a lot faster to do but it requires a duo partner. Create a private free for all match on the map underground. Both pick a survivor with the grenade launcher equipped and set the match options to 20 minutes with 100 kills.

Run to the middle (under the bridge) and wait for the other person to get ready. Get your grenade launcher out, aim at your duo partner and shoot each other at roughly the same time.

If done correctly you will get some XP for explosion kill, revenge, etc, but the main reason why we do this is for double trouble (kill your attacker at the same time you are killed). This alone will net you 600 XP per kill and that does not include the other bonuses you get on top of it.

double trouble will be your main source of XP. If you keep doing this for 20 minutes at a decent pace, you can get anywhere between 80k and 100k XP per 20 minutes.

make sure to equip the perk accomplished killer, this will give you extra XP per kill.

Some general tips for doing it the this way:

• Dont stand too close
  You should not be dying from your own grenade.
  
• You can aim for the body
  Its a sticky grenade so you don't have to shoot the ground if that helps you aim.
  
• Timing
  There is some leeway in this, you don't need to be dying at the exact same time. As long as you kill your opponent before you respawn.
  
• Ammo
  You each have only one grenade. If one of you survives, it's best for them to either fall into the water or find a nearby yellow crate to replenish their ammo.

If you don't want to grind that long there is also a guide on how to import a save file to get both true commitment and shopaholic. https://node2.projectplanet.cn/@steamcommunity.com/sharedfiles/filedetails/?id=225721044

"Reach level 10 in multiplayer."
You will get this on your way to LV60.

"Buy every upgrade and character in multiplayer."

You are going to need a lot of scrap for this, and be LV60.
to grind scrap just load up any private match on a map (i prefere underground) and run around collecting the yellow scrap crates. There are 5 on each map that will respawn after some time, Allowing you to keep running around the map collecting them.

For underground there are 1 on each side of the turret,
1 On each side of the docks,
And 1 on the far end of the boat

Once you got some scrap start buying characters. i am not 100% sure as to what exactly triggers the achievement since mine din't unlock until i restarted the game. But i am sure that you need all characters except the Oni general.

when you have bought all the charterers try restarting your game. If it does not unlock try buying some attachments for guns and periodically restarting until you get it.


"Purchase a new multiplayer character."
You will get this by going for shopaholic.

I hope this guide can help some people get the achievements faster. Feel free to suggest improvements that could be made too the guide. And have a nice day. :)