Why not random?

Posted by Michael on May 25th, 2006, in Development

The basic problem of autonomous behaviour in Drama Princess is that of action selection. The most simple solution is randomness. And we know from experience that randomness is also very believable, more so, often, than much more complex systems.

For reasons that are mostly related to narrative, total randomness is not desirable.
These reasons include the desire for

  • Consistent behaviour
    It’s easy to make an insane or hysteric character. Pure randomness will get you very close to this. But we do not want to limit our narrative potential. Sane characters display a certain consistency in their behaviour.
    We have already suggested a simple solution for consistency.
  • Diverse personalities
    Both the story and the player’s empathy improve as the characters display a recognisable personality. To express this personality, a character’s selection logic would need to prefer certain actions over others. To define this personality, the author would need to be able to define this preference. On the other hand giving each character a different set of actions would also immediately give them a different personality. And the outer appearance of a character (model, textures, animations) goes a long way as well in this area.
    The re-usability requirement of Drama Princess, however, would benefit from characters that share action sets and assets.
  • Character growth
    Also important for both story and empathy is the perception of growth or evolution in a character. Especially if this growth happens as a result of interaction with the player.
    To implement growth as a constraint on randomness, the selection preferences mentioned above would need to be dynamic. Not randomly dynamic but according to a gradual shift. Perhaps one could think of morphing as a metaphor: you could morph one set of actions or preferences gradually into another. In the case of preferences, this could be as simple as increasing or decreasing a bunch of numbers, each of which defines the probability that an action will be selected.
Comment by Patrick

Posted on June 2, 2006 at 4:06 am

I’m considering one random process in the drama engine I’m designing, based on the variable Fear. Fear determines whether or not the character breaks a social rule at a given time, its like an inclination wildcard.

Comment by Michael

Posted on June 2, 2006 at 9:50 am

Do you mean that a character will behave more randomly if its fear increases? So that it seems nervous?

Comment by Patrick

Posted on June 2, 2006 at 11:29 pm

It depends on the rule, some rules would apply an inversion operator, so that more fear means a higher chance of acting out. Conversely the actor’s fear would restrain him or her to act in line with whatever they’re “supposed to be doing”. I’m deconstructing fairy tales as part of my source, I’ll blog about this a bit later.

Either way the effect is local, as you describe, sort of like Perlin Noise applies to character behavior.

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