Modeling spells/skills as collections of affects

[Brian Price]

In the codebases I've seen thus far, spells and skills are largely
hardcoded.  I would like to implement a system where they were instead
parameterized and stored in the mud's database.  One approach to this
would be to describe spells and skills as a collection of
event-dependant affects.  To implement this, the definition of affects
would need to be expanded a bit, for example, a mud object's location
would be an affectable state.  Also, there would need to be a system
of events which would trigger the various affects.  

Has such a system been implemented elsewhere?  If not, any thoughts on
how such a system could/should be implemented?

Thanks,
Brian Price aka Delver <blprice at bedford.net>