Your series should have a central situation.
This is the situation in which the characters find themselves. It’s why they are who they are and do what they do.
For example, in Miami Vice, the central situation is that Crockett and Tubbs are undercover vice cops in Miami.
Supernatural - Sam and Dean are Hunters who travel across America in search of supernatural beings.
The X Files - Mulder and Scully are FBI agents tasked with investigating paranormal or unusual cases.
The Walking Dead - the characters are trying to survive a zombie apocalypse.
This situation should be one which will generate stories. The most obvious way to do this is to put your characters in a central situation in which they either:
a) willingly face the A and C Story problems as part of their job (i.e. detective and cop stories)
b) unwillingly face the A and C Story problems as part of their survival (i.e. ‘survivor’ stories)
There is an inherent problem with survivor stories. If the characters become too good at survival or reach relative safety, all the conflict will disappear.
This happened in Season Two of The Walking Dead. The group spent most of the season on a farm which was relatively safe from zombies. So the central situation (surviving the zombie apocalypse) was removed and the show became centered on the group’s internal conflicts. As a result, the tension flagged.
If your central situation involves survival, make sure the tension stays ratcheted up. Survival is only interesting if there is a chance of non-survival.
Other ways to make sure your characters face the A and C Stories is to force them to do so by their emotions.
If your series is a Romance or a Drama, the characters may take certain paths into the story arcs because they are compelled to do so by their love or hatred or jealousy of other characters. Think about Desperate Housewives and how many plot arcs came about because one character wanted revenge on another or because a character wanted love, or security, or money.
For more ideas along these lines, watch the new series of Dallas and look at what motivates the main characters. Or watch reruns of series like Dynasty or Dirty Sexy Money.
In the 19th Century, Georges Polti wrote a list of 36 Dramatic Situations. If you’re stuck for ideas when deciding your situations or characters’ motivations, a glance down the list could spark an idea.
3. Crime Pursued by Vengeance
4. Vengeance Taken for Kindred Upon Kindred
7. Falling Prey to Cruelty or Misfortune
9. Daring Enterprise
11. The Enigma
13. Enmity of Kinsmen
14. Rivalry of Kinsmen
15. Murderous Adultery
17. Fatal Imprudence
18. Involuntary Crimes of Love
19. Slaying of a Kinsman Unrecognised
20. Self-Sacrifice for an Ideal
21. Self-Sacrifice for Kindred
22. All Sacrificed for Passion
23. Necessity of Sacrificing Loved Ones
24. Rivalry of Superior and Inferior
26. Crimes of Love
27. Discovery of the Dishonour of a Loved One
28. Obstacles to Love
29. An Enemy Loved
31. Conflict With a God
32. Mistaken Jealousy
33. Erroneous Judgement
35. Recovery of a Lost One
36. Loss of Loved Ones
The language may be a little archaic but these situations cover the basic human desires which will drive your characters through your story.
Create a solid central situation and motivate your characters to move through your A,B,and C Story arcs with their own personal agendas and you will have a conflict-driven series.
Now it’s time to start writing...