Let's make characters that act human instead of merely look like they are

Characters have their own personalities. I learn this more as I write. Sometimes, they speak to me through how they do things. The little qualities which make a person, even someone who appears common, to be unique. Everyone is not the same, but that isn't an opinion focused merely on looks. Habits can be another way, but the way that a character phrases comments or thinks about something can build who they are better than other attempt.

Character building for me starts with a person I know. I ask myself what they would do in a specific situation. When I haven't attempted this type of "in this person's shoes" character, my story usually fails. Why? I believe it has to do with the fact that I trust the plot too much and don't let the characters face adversity of each challenge in their own, individualistic way.

An example of a story common character who is merely doing what the plot wants: Guy moves forward, puts his hand on the door, opens it to reveal...

I have a friend named Mike. This is what I believe he would do in that same situation: Mike would see the door, grab a bat, back away from the door, then move close toward the door. No investigation, no need for explanation. Get the hell out.

That makes him more realistic. The only reason he would go through the door is if he saw someone hurt and wanted to help.

A horror story example:

The movie "House" - Guy shuts a door as a thing that looks like H.R. Gieger's Aliens tries to come through the closet. Afterward, the guy sets up cameras, trying to capture the thing on film to prove that it exists.

Mike gets the door shut, burns down the damn house. The last thing he does is try to investigate anything. Mike, who is a Viet Nam vet and has faced a lot of heavy stuff in his time, would say: "Investigation done" and light the match.

Whether this story is a gigantic, fantastic story or not, it needs human characters who act human in order to survive.

Otherwise it is a common story that doesn't work that the audience does not fully identify with.