  Nguyen et al. [1] introduced altruistic hedonic games in which agents'
utilities depend not only on their own preferences but also on those of their
friends in the same coalition. We propose to extend their model to coalition
formation games in general, considering also the friends in other coalitions.
Comparing our model to altruistic hedonic games, we argue that excluding some
friends from the altruistic behavior of an agent is a major disadvantage that
comes with the restriction to hedonic games. After introducing our model and
showing some desirable properties, we additionally study some common stability
notions and provide a computational analysis of the associated verification and
existence problems.
