From the rulebook:
Students participate in OH MY DEER as wildlife managers. They are placed in charge of the management of a deer herd and must make the decisions that affect the size of the population and fate of individuals in the herd. Through participation and discussion, students achieve an intuitive understanding of some of the fundamental areas of wildlife management and have fun in the process.

The rulebook recommends playing the game in groups of 5 or 6 with one copy of the game per team with each team managing one deer herd.