Players are of course the core of what makes a MUD game entertaining.
The MUD consists of lots of AI characters which behave unpredictably
but no-one behaves more unpredictably than a human on-line
player. It is difficult to code mood swings into AI characters
but they are ever present in human players.
Immortal players are the players who actually administrate
the MUD game itself, they set quests, ensure rules are adhered
to. Immortals cannot advance your character nor can they create
magical items or resurrect characters which have died through
Be careful what you do, immortal characters can go invisilble
in a split second and teleport to locations to ensure fights
etc are fair and they cannot be detected with 'detect invis'
or be seen on the 'who 0' list.