Combat Ratings: six special, double-cost skills that are based on two stats apiece. They are Melee Combat, Grab/Throw, Ranged Combat, Dodge, Bravery and Leadership.
Enchantment: a spell bound into a physical object that lasts as long as the mage wishes it to, but which still penalizes their spellcasting ability in a small way because of the drain on their magical energies. If maintained long enough, an enchantment will become independent of its creator, but this can take more than a year.
Exhausted: completely out of Fatigue points. An exhausted character is at -2 to all actions and cannot acquire Focus. If forced to spend another Fatigue, they fall unconscious at the end of the round.
Fatigue: Fatigue points represent a character's reserves of energy. When you have spent all of your Fatigue, you are exhausted and at -2 to all actions. If forced to spend another Fatigue while exhausted, you fall unconscious at the end of the round.
Feral rodents: refers to ordinary, unintelligent mice and rats. Feral rodents instinctively fear the intelligent, talking sort.
First Ones: the first royal mice to come to Hyperborea, long ago. They founded the various kingdoms of the valley and then ascended to godhood.
Focus: when a character is calm, collected and ready to act, they are said to possess Focus. Focus can be expended to trigger many abilities. It takes an action or spending a Fatigue to recover Focus. Focus can only be expended once per turn, although it may be recovered again instantly by spending Fatigue.
Focus Action: a Primary Action which can be turned into a Free Action by spending Focus.
Forsaken: those mice and rats whose mental and magical capabilities are so weak that they often revert to the behavior of their feral kin. Any children that they have may be completely feral.
Free Action: a minor action which takes little time. Characters can perform several free actions in the same turn, as long as they are all different.
Hyperborea: the sheltered valley in which the game is set.
Primary Action: an action which takes up most of the character's turn. A character can only perform one Primary Action per turn.
Size: a rating representing a creature's size, with a mouse being Size 0. Something considerably larger than a mouse will have a positive Size (rats are +1 or +2) while smaller creatures will have a negative rating.
White Lords: refers to royal mice and, to a lesser extent, any white mouse in a position of rulership.