Altruistic coordination is the study of how individual altruists should act when the impact of each person's decisions depends on the actions of other altruists. Such coordination could take many forms, including philanthropic coordination; moral trade; attempting to consider comparative advantage and replaceability rather than just personal fit; building "community capital"; and taking a "portfolio approach".^[1]

This coordination could be achieved via actual discussion between the relevant altruists. Alternatively, an altruist could simply try to roughly predict  how their actions will affect the actions of other altruists, or follow rules of thumb intended to aid in altruistic coordination.

Altruists often fail to attempt altruistic coordination, instead taking actions based on what would be the best action if other people aiming to do good weren’t responding to what they do. Todd refers to this as "single-player thinking".^[1] Additionally, even when a person does attempt altruistic coordination, it can be difficult to work precisely how to do so, and the communication and trust involved in good coordination can be costly to maintain. As more people try to work together to do good, it appears that achieving low-cost coordination will be a difficult but important problem to solve (see also value of movement growth).