Well, this is a very complicated question. First of all, what is “moral”?
Moral: (n) focused on the fundamental principles of right conduct rather than on legalities, enactment, or custom.
Ok, so moral characters are concerned with right-mindedness; they care about doing the right thing. Right? Notice that, by the definition, morality supersedes legality and customs, which are constraints imposed on people by society. These constraints may be immoral like the military draft which forces people into a situation where they may have to kill another person (killing is pretty much immoral, folks) or the common custom of the “little white lie”. And because these constraints may be immoral, a moral character may, on occasion (or all the time), ignore them.
What are the principles of moral behavior? How can you tell, basically, if a character is moral?
“If you ask anyone, ‘What is morality based on?’ these are the two factors that always come out: One is Reciprocity, and associated with it is a sense of justice and a sense of fairness, and the other one is Empathy and compassion. Human morality is more than this, but if you would remove these two pillars, there would be not much remaining, I think, and so they are absolutely essential.” - Frans de Waal
What do Reciprocity and Empathy mean?
Reciprocity: (n) responding to a positive action with another positive action, rewarding kind action
Empathy: (n) the ability to understand and share the feelings of another
If your character is moral, he or she will almost certainly have a sense of fairness and compassion. Both of these are considered part of the Seven High Virtues, with Empathy commonly referred to as “Love” or “Charity”, and Reciprocity most often called “Justice”. Very moral characters will, most likely, have either Love, Charity, or Justice as their peak virtue.
Moral characters are often good listeners. They care for other people, and they want to do right by them. They are willing to take action to create positive outcomes for others. They have little to no concern for themselves.
Don’t get us wrong, morality is a sliding scale. Many heroic characters are basically moral, though they may sometimes kill, lie, steal, or cheat depending on what life-threatening or otherwise difficult situation has arisen. But if you’re looking for straight-up a moral character, the most common indicator will always be cooperation.
Does your character play well with others?
Morality arises from the need for cooperation, and the understanding of cooperation as essential to human interaction. There is no need to be moral if you are, for example, the last human on Earth. Who is there to be moral with or to? Therefore, moral characters desire to interact with others in a positive way. Immoral characters don’t care about offending or harming others, so they are cool with interacting in a negative way.
Moral heroic characters are often great leaders because they are good at cooperating. Immoral heroic characters are often loners because they are awful at cooperating.
Alright, so if your character moral, they will (most likely):
It is worth noting that morality is different for different people in different places at different times in history. Generally, there are universal ideas of morality instilled within us from infancy (these are cooperation, justice, compassion, a sense of “rightness” and “wrongness”, etc). Deciding what you, as a writer, think of as “moral” is fundamental in determining the morality of the character in question. We can’t tell you what moral is for you in your story or for yourself, but once you decide that, you will be able to define your character’s morality.
If you are very interested in determining the morality of your character, you can take this quiz for yourself and/or for your character to help you decide. Be warned that some of the questions may not be truly applicable to your characters (for instance, whether or not stem cell research is wrong may not be an issue in your world because there is no stem cell research), but do your best to answer for your character in those situations.