This command is an extensive interface to your knowledge of spells. Some caster classes use it to learn spells, some don't. This command is essential for sorcerers, warlocks, psions and psywarriors. Without spell being on their mastered list they won't be able to cast it. Mages can expand their spell knowledge through this command, although the main way they obtain new spells is through the spellbook.

master
Without an argument this command will display all available knowledge slots for each level.

master list
This will display list of spells you know grouped by level.

master level NUMBER
This will list all the spells that you could master of level NUMBER.

master SPELL
With this command you will commit to learning a SPELL.

master forget SPELL
Once per 9 hours you can forget a SPELL and learn a new one.