Preference utilitarianism is one of the most popular forms of utilitarianism

Utilitarianism

Utilitarianism is an ethical theory holding that the proper course of action is the one that maximizes the overall "happiness", by whatever means necessary. It is thus a form of consequentialism, meaning that the moral worth of an action is determined only by its resulting outcome, and that one can...

 in contemporary philosophy. Unlike classical utilitarianism, which defines right actions as those that maximize pleasure and minimize pain, preference utilitarianism promotes actions that fulfill the interests (preferences) of those beings involved. The beings may be rational

Rational agent

In economics, game theory, decision theory, and artificial intelligence, a rational agent is an agent which has clear preferences, models uncertainty via expected values, and always chooses to perform the action that results in the optimal outcome for itself from among all feasible actions...

, that is to say, their interests may be carefully selected based on future projections, but this is not compulsory; here, the definition of "party" extends to all sentient beings, even those living solely in the present.