A preamble is an introductory, usually ceremonial, part of the text of a written document (deeds, statutes or legal regulations, such as laws and constitutions), which sets out the intention, meaning or purpose of the following text after the preamble.
The preambles are usually contained in the constitutions of states. They contain both a historical part, which refers to previous state institutions and justifies the current state existence, and a part that contains the basic values and principles of the state and the general definition of fundamental rights and obligations of citizens. For legislation, the binding nature of the preambles is questionable, but it can always serve as an interpretative tool.
Moral altruism they helped informed only by ethical consideration regardless of any rivalry between the teams. Moral altruism is the highest calling in altruism(helping others selflessly) the team did not consider that if they failed to provide shelter to the other team it would get some advantage over it.