We consider the abstract structure of the monoid ℳ of misère impartial game values. We present several new results, including a proof that the group of fractions ofℳis almost torsion-free, a method of calculating the number of distinct games born by day 7, and some new results on the structure of prime games. We also include proofs of a few older results due to Conway, such as the cancellation theorem, that are essential to the analysis, but whose proofs are not readily available in the literature.