The supposed difference between Rule Utilitarianism and Act Utilitarianism For rule utilitarians, the correctness of a rule is determined by the amount of good it brings about when followed. In contrast, act utilitarians judge an act in terms of the consequences of that act alone
Average utilitarianism. Average utilitarianism (also averagism) values the maximization of the average utility among a group's members. So a group of 100 people each with 100 hedons (or "happiness points") is judged as preferable to a group of 1000 people with 99 hedons each.
Sentient Utilitarianism This is a type of utilitarianism that gives equal consideration to all sentient beings and not just humans in particular. Therefore, this utilitarian view can be incorporated in with all of the others - when considering a type of utilitarianism, you must ask whether or not it caters for animals other than humans, whether or not it is 'sentient utilitarianism'.
Total utilitarianism Total utility (also totalism) is a method of applying utilitarianism to a group to work out what the best set of outcomes would be. It assumes that the target utility is the maximum utility across the population based on adding all the separate utilities of each individual together.
Two-level utilitarianism is virtually a synthesis of the opposing doctrines of act utilitarianism and rule utilitarianism. Act utilitarianism states that in all cases the morally right action is the one which produces the most pleasure, whereas rule utilitarianism states that the morally right action is the one that is in accordance with a moral rule whose general observance would create the most happiness.