@Anette I think what made raiding in midkemia possible was the fact that you couldn't create a giant clot of guards in one room. You had to be strategic about placements because you could only place up to five in a single room. Of course anything past that caused them to start missing the attackers which I had mixed feelings about. Another thing was each particular guard type had a unique role e.g. revealing black wind/phase/masked players, resurrecting dead guards, blocking exits, etc. and that was part of the fun in playing defense.
I feel that in Imperian, a lot of the people that were interested in raids either moved to another mud or have taken a break. Maybe there is a solution we could come up with that would entice players, who may not necessarily be interested in pk 24/7 but would like to get their feet wet once in awhile.