Does your character 'Mary' continue down the path of alcoholism, and choose to prostitute herself when she's fired from her job? Or does she join AA and rise on her 'arc'. Whether your characters be normal human beings (Define normal human being*, I dare ya'.) or they show traits of mental disorder, agoraphobia, Borderline Personality Disorder, Bi-polar, post traumatic stress disorder, et cetera, they must continue unless they choose, or you, as the 'boss' playwright, give them another path. Using the aforementioned conditions can be tricky, because BPD victims can change their behavior in a heartbeat. "How dare you leave me! Get out!" Alcoholics can be great actors. Bi-polar victims alternate between mania and depression. There are a wide range of mental disorders where your characters can find themselves, or not, and your audience is lost, wondering, and wandering, looking for the exit at intermission.
Your characters can be at home behind the counter of a diner, or in a prison cell, or in a bingo parlor. Establish your character's geography. When you take 'Luke' out of his 'home', say behind a skid row bar and in the next scene put him in a Hilton hotel room, find a good reason and time for the change: don't confuse your audience or you won't have them very long.
Continuity of character interaction: 'Jill' hates it when 'Jack' is kind and gentle to her one moment and in the next moment he is treating her cruelly and in-humanly and she is loving it (barring some mental disorder for both characters) the audience will be confused and out of focus. You have lost their confidence in your ability to hold them.
If your character, in her dialogue states, "Today is Friday. I'll see you at noon for lunch. We'll have tuna on rye.", but the calendar on her office wall says it's Tuesday, and the clock reads one pm, you've lost your audience again.
If Henry, fourteen years old, tells Mercedes that his brother died sixty years ago in World War II, you've derailed the audience again. How old was Henry's brother when he died of his wounds on the beaches of Iwo Jima? How old was mama and dada when they had Henry. Yeah, I know. They adopted Henry.
From when will you stop with the abuse of continuity already? And you haven't even established that I'm yiddish. (From Brooklyn? No, Crown Heights.)
When your publisher sends you a proof? No. You will still find errors in continuity... : verbs, here and there a comma, colons, pronouns, adverbs, accent grav, et cetera.
Writing is re-writing.
*To be a normal human being are you devoid of one or more or all of the following; schizoid, Pyromania, psychologically imbalanced, mentally ill, Bi-polar, PTSD, et cetera?