Stories are about aspects of human experience. Characters are the essential core of a story. A narrative about the events of a chemical reaction cannot be a story no matter how those events are plotted, because there are no sapient actors. The chemicals are not choosing to create their circumstances, so we learn nothing of ourselves and our beliefs about human life. For example compare these three scenarios:

Romeo and Juliet fall in love despite coming from rival clans,

their passions will burn and they will take risks in order to stay together,

Resulting in
their committing suicide as the only way to achieve unity.

wood is set alight,

it will burn,

Resulting in

the wood finds itself set alight,

it experiences fear, anger, and grief as it is consumed by the flame,

Resulting in
the wood having to come to terms with these feelings before turning into ash.

You will note that as soon as the wood has been anthropomorphised, it simply acts in the stead of a human being.

A character's focus will express a certain personal theme. The story's theme will give the character's actions meaning. An audience can find meaning where creators may have consciously attempted to disallow meaning through apparently random selection. Nevertheless, creators need to respect audience's attempts to meet them half way.

Within a digital creation a character can unify the events in a story if every event is meant to reveal who that character is, the sorts of things that they do, and why they do it (their personal theme), like a jigsaw puzzle with a face as the recognisable central feature around which all the pieces are put into place. However, character can be used even more potently than that to interest an audience in discovering all the pieces of the story.

If a character has an interesting objective and powerful reasons for being motivated to see that objective fulflled, then the audience is likely to take on that character's objective as their own. They will be motivated to explore the story in order to have the satisfaction of seeing how the character will achieve or perhaps fail achieving their objectives and why. The traditional story challenges characters must face: character vs. character, character vs. nature, character vs. society, character vs. self, are the processes they must pass through in order to achieve their objectives, but also generate greater stakes in seeing the character succeed. The character of Tex Murphy generates this sort of interest in Under a Killing Moon [Acc94].

Whether or not it is a complete depiction of human motivation a nice source to draw ideas from for story objectives is the work by one of the founders of Humanistic Psychology, Abraham Maslow, in particular his enumeration of basic human needs:

Maslow's Hierarchy of Needs

  1. Physiological Needs
    (food, water, oxygen, fundamental life or death needs)
  2. Safety Needs
    (security, stability, protection)
  3. Belongingness and Love Needs
    (giving and receiving attention)
  4. Esteem Needs
    (achievement, confidence, independence, recognition, appreciation)
  5. Self-Actualisation Needs
    (people doing what they are individually fitted for and so achieving peace and fulfilment)

[Mas54, Derived from Chapter 5]

So perhaps in a digital story several characters are presented as having just crashed onto a mountain top and must now struggle to survive (physiological needs). The audience will then anxiously follow in their search to find food. Given the precariousness of their situation perhaps some of the characters begin to feel desperate to form emotional bonds, so as to reassure themselves that they can live through this (safety and love needs). The audience will then be interested in seeing the process of one character reaching out to another in complete vulnerability.

Within Odysseus, She Odysseus misses her family and after a long hard war, wants nothing more than to return home to the love of her husband and daughter (belongingness and love needs). Due to the invasion of the suitors in Odysseus' home, her daughter's story is one motivated by a need to find the protection of her mother (safety needs).