When utility is used in game theory, it doesn't have to apply to utility that you gain personally, but instead can apply to anything you value. Call this inclusive utility and personal utility the value you gain from the situation.

Changing the altruism levels changes the inclusive utilities that each decision offers (even though the personal utility remains the same), so even with the same probability you should take different odds.

Inclusive utility can be replaced with personal utility only for selfish agents.