The realms of Necromundus are overseen by the forces of the Ascendant (Good) and Descendant (Evil) aspects. Their servants - angels and demons, respectively - are able to travel to their associated aspects and do battle against manifestations of good and evil. Their victories help tilt the balance of Goodness or Evilness toward one alignment or another in all the realms.
But even the lesser inhabitants of the world of the dead are able to contribute toward the dominance of either alignment.
Many creatures drop Goodness Tithe and Evil's Due vouchers, which can be redeemed in the Portal Plaza for points. Players can have both good and evil points. Each day, the total for both alignments is tabulated.
Type +alignment in-game for a display on the overall balance between good and evil. For your personal balance, type +alignment/me.