To unlock the "SURVIVORS" trophy in Detroit: Become Human, you must make sure that all principal characters make it to the end of the game. This is not just the three playable characters
: On my first run through I did not unlock this trophy because characters directly tied to either Kara, Connor or Markus were killed before the end of the game. So make sure the following characters make it as well as the protagonists: Hank, Alice, Luther, North, Josh, Simon.
Here are some characters that can definitely die without repercussion, as the trophy still unlocked for me:
Below are some examples of where the protagonists' allies can get killed and some advice on how to avoid that, but there are hundreds of possibilities in this game. I will update with the ones that I find on repeated playthroughs.
As a general rule in a potentially lethal incident, avoid conflict and always choose to protect your allies however you can, in most cases you will only have to perform some QTEs anyway. The game leaves you with more ways out than you might think. Generally you should keep your allies loyal and friendly to avoid conflicts as well, and get the public on the side of the androids through peaceful non-violent protest. In other words, you should go for this trophy on your "Good ending" run; trophies that require violence or Connor's various deaths should be held back for a mop-up playthrough.Markus' allies:
Alice and Luther (credit to SolaceCreed for some Alice tips):