This guide isn't here to explain to you the basics on how to play this game, how to complete this or that objective or how to solo the game. what this guide will tell you, are some logical advices that you should know about when playing in multiplayer.
This guide will be very straightforward, it will explain to you what you should do in which situation, and why you should do so.

On difficult planets, starting lvl 8 & above, if unfortunately someone let an enemy trigger the alarm, don't try to fight : run, simply because the alarm is going to bring more scouts which will trigger again the alarm, etc, while bringing some powerful enemies.
Since the number of enemies is unlimited, you cannot fight them and will be overwhelmed and killed. In this case, do not use Stratagems, unless it's necessary because it will force your teammates to wait, and you don't want to wait.

Also, when there's only one helldiver left, just run away from the enemies, don't fight back unless they block your way to safety. When the situation calmed down, you can call your team back.

When trying to defend an objective, and you have triggered the alarm, be sure to have your entire team on the same side. Why ? you may ask. Simply because in multiplayer, the camera tries to have everyone in sight at the same time, so if you try to go on opposite direction, there will be a moment where all of you get stuck, unable to run on one side, and cornered by the enemy on the other side, and everyone will die.

Sometimes, when you go in multiplayer, you'll find a guy with a shotgun. This guy will become the main reason of your countless death in no time.
When you have a shotgun, if you shoot once at your friend, they will instantly die.
So, for all the shotgunners among us, please learn to use your shotgun properly. Meaning, if there's one little bug attacking your friend, just let him kill it by using his weapon or melee, do not try to kill the bug, and by the same occasion, your friend.

I have seen this one many times, and what generally comes after that is the mission failure screen.
When playing HELLDIVERS in multiplayer, you have to know that there are different types of enemies, with the most dangerous one being the scout (I call him that way, but they have different names for each races) that will trigger the alarm and bring all the huge ass enemies on your face.

Now the important point to remember here, is that you should always kill these scouts to prevent the massive enemy spawn.

What does that have to do with multiplayer ? Well, if there's a scout entering your line of sight and you cannot kill it (generally because you have to reload) and there's a player right behind you (so you got "player" - "you" in between - "scout") just get out of here asap, run or take cover, but let the other player kill the scout. Don't just stand in there blocking his way, risking to get either killed or to have the scout triggering the alarm and getting killed even more.

1) When the alarm have been triggered and you are on a planet lvl 8 or above, just run to safety, don't fight back because there's an unlimited amount of enemies.
2) Try to have the whole team in a restricted area, so you don't get stuck because of that camera preventing you to run and giving you only one way to go with 1000 enemies.
3) Don't shoot on your friends with a shotgun (or with anything else btw) because it will kill them in one shot.
4) If you are between a scout and a teammate, and you cannot kill the scout, move asap to let the other player kill the scout before it triggers the alarm.


I will try to update this guide if I find other interesting tips and will also take your suggestions if you have one.