The fundamental game mechanics of the MUD are based on a 'stat/skill' division, with a player's stats (statistics) relating to intrinsic properties, being semi-permanent, and skills (relating to aptitudes) increased by spending experience points to self-teach, or to learn from other player/non-player characters. Skill abilities are based on a diminishing returns system, in which a character's 'bonus', or ability to perform a certain task, is calculated on a logarithmic basis from the character's skill level and a geometric mean of related stats. Levels are uncapped, but also rise in experience point cost per level.